Afrin Kamal is a board-certified gastroenterologist, who trained at Washington University in internal medicine, Cleveland Clinic in gastroenterology/hepatology, and most recently Stanford University in esophageal and motility diseases. Afrin shares a clinical passion in esophageal motility diseases with an an overlapping interest in health services and outcomes research.

Clinical Focus

  • Gastroenterology
  • Benign esophageal diseases
  • Esophageal motility

Academic Appointments

Boards, Advisory Committees, Professional Organizations

  • Trainee Committee member, American College of Gastroenterology (2018 - Present)

Professional Education

  • Fellowship: Cleveland Clinic Foundation Hospital (2018) OH
  • Fellowship: Stanford University Gastroenterology Fellowship (2019) CA
  • Board Certification: American Board of Internal Medicine, Gastroenterology (2018)
  • Residency: Washington University School Of Medicine Registrar (2014) MO
  • Board Certification, Gastroenterology, American Board of Internal Medicine (2018)
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2014)
  • Medical Education: University of Missouri (2011) MO

Clinical Trials

  • Applying Nutrient Drink Test in Understanding Pathophysiology of CVS Recruiting

    Cyclic vomiting syndrome is a disorder characterized by nausea and vomiting, separated by periods without any symptoms. There is very little research on this field at this point and most doctors do not fully understand the disorder. The goal of this study is to assess how the stomach empties food. Participants will be asked to participate in this study because either (a) they have been diagnosed and/or treated for cyclic vomiting syndrome in the past, or (b) they are physically healthy. The study seeks to compare how a healthy person's stomach empties to how the stomach of someone with cyclic vomiting disorder empties.

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All Publications

  • Question Prompt List as a Communication Tool for Adults with Gastroesophageal Reflux Disease Incorporation of Patients' Perspectives. Journal of clinical gastroenterology Kamal, A., Achkar, E., Carlson, D., Clarke, J., Fass, R., Gyawali, C. P., Katzka, D. A., Patel, D., Penagini, R., Rezaie, A., Roman, S., Savarino, E., Shaheen, N. J., Triadafilopoulos, G. 2021


    BACKGROUND: Question prompt lists (QPLs) are structured sets of disease-specific questions intended for patient use, enhancing the patient-physician communication by encouraging patients to ask relevant questions during a consultation. Recently, a preliminary 78 question gastroesophageal reflux disease (GERD) specific QPL was created by 12 esophageal experts through a modified Delphi (RAND/University of California, Los Angeles) technique. Patients' perspectives and opinions on each question, however, had not been accounted for in the preliminary expert' version.AIM: The aim was to modify a preliminary experts' QPL, specific to adults with GERD, following patient perspectives and opinions.METHODS: A preliminary GERD QPL was modified through patient input and opinions. Thirty-eight patients with a clinical diagnosis of GERD followed at Stanford University Esophageal Clinic between January and November 2019 were consented to modify the preliminary 78 question expert QPL version. After receiving the QPL in Qualtrics (Provo, UT) by a direct e-mail invitation, patients independently rated questions on a 5-point Likert scale, where 1="should not be included," 2="unimportant," 3="don't know/depends," 4="important," and 5="essential." Questions were accepted for inclusion in the QPL with an a priori interagreement of 80% ranking in the range of 4 to 5. At the end, patients were encouraged to propose additional questions to incorporate into the QPL by open-endedly asking "Are there questions we didn't ask, that you think we should?"RESULTS: Twenty-three patients with GERD (19 female, median age 64) fully participated and modified the existing QPL (60.5%). Of the 78 questions from the preliminary GERD QPL, 66 questions (84.6%) were accepted for inclusion. The question with the highest agreement among patients rating a question as essential consisted of "what habits, food, and drinks do I have to avoid?" (82.6%). Questions eliminated because of disagreement included "What is the natural history of GERD," "Do I have a high chance to die from my Barrett's?," and "Why are you prescribing an antidepressant to treat my GERD?" Nine patients suggested additional questions totaling to 16 separate questions, including "What type of surgeries are there to help GERD?," "What stage is my GERD?," "What are the odds/percentage of getting cancer from GERD?" Incorporating the suggested questions, the final GERD QPL-created by esophageal experts and modified by patients-consisted of 82 questions.CONCLUSION: Esophageal experts and GERD patients have a high level of agreement on important questions, though there is some variation in perspective. Future studies can simplify this list and measure the impact of a shared GERD QPL on patients' decisional conflict and perceived involvement in care.

    View details for DOI 10.1097/MCG.0000000000001613

    View details for PubMedID 34653066

  • The Stanford Multidisciplinary Swallowing Disorders Center. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Nandwani, M., Dewan, K., Starmer, H., Kamal, A. N., Clarke, J. O. 2021

    View details for DOI 10.1016/j.cgh.2021.04.025

    View details for PubMedID 33887474

  • Development of quality indicators for the diagnosis and management of achalasia. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society Kamal, A. N., Kathpalia, P., Otaki, F., Bredenoord, A. J., Castell, D. O., Clarke, J. O., Falk, G. W., Fass, R., Prakash Gyawali, C., Kahrilas, P. J., Katz, P. O., Katzka, D. A., Pandolfino, J. E., Penagini, R., Richter, J. E., Roman, S., Savarino, E., Triadafilopoulos, G., Vaezi, M. F., Vela, M. F., Leiman, D. A. 2021: e14118


    BACKGROUND: The management of achalasia has improved due to diagnostic and therapeutic innovations. However, variability in care delivery remains and no established measures defining quality of care for this population exist. We aimed to use formal methodology to establish quality indicators for achalasia patients.METHODS: Quality indicator concepts were identified from the literature, consensus guidelines and clinical experts. Using RAND/University of California, Los Angeles (UCLA) Appropriateness Method, experts in achalasia independently ranked proposed concepts in a two-round modified Delphi process based on 1) importance, 2) scientific acceptability, 3) usability, and 4) feasibility. Highly valid measures required strict agreement (≧ 80% of panelists) in the range of 7-9 for across all four categories.KEY RESULTS: There were 17 experts who rated 26 proposed quality indicator topics. In round one, 2 (8%) quality measures were rated valid. In round two, 19 measures were modified based on panel suggestions, and experts rated 10 (53%) of these measures as valid, resulting in a total of 12 quality indicators. Two measures pertained to patient education and five to diagnosis, including discussing treatment options with risk and benefits and using the most recent version of the Chicago Classification to define achalasia phenotypes, respectively. Other indicators pertained to treatment options, such as the use of botulinum toxin for those not considered surgical candidates and management of reflux following achalasia treatment.CONCLUSIONS & INFERENCES: Using a robust methodology, achalasia quality indicators were identified, which can form the basis for establishing quality gaps and generating fully specified quality measures.

    View details for DOI 10.1111/nmo.14118

    View details for PubMedID 33720448

  • Severe gastroparesis is associated with an increased incidence of slow-transit constipation as measured by wireless motility capsule. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society Radetic, M., Kamal, A., Rouphael, C., Kou, L., Lyu, R., Cline, M. 2020: e14045


    BACKGROUND: Dysmotility in one region of the gastrointestinal tract has been found to predispose patients to developing motility disorders in other gastrointestinal segments. However, few studies have evaluated the relationship between gastroparesis and constipation.METHODS: Retrospective review of 224 patients who completed 4-hour, solid-phase gastric emptying scintigraphy (GES), and wireless motility capsule (WMC) testing to evaluate for gastroparesis and slow-transit constipation, respectively. When available, anorectal manometry data were reviewed to evaluate for dyssynergic defecation. Patients were divided into two groups based on the results of the GES: 101 patients with normal gastric emptying and 123 patients with gastroparesis (stratified by severity). Differences in constipation rates were compared between the groups.KEY RESULTS: Slow-transit constipation was more common in the gastroparesis group, but statistical significance was not reached (42.3% vs 34.7%, p=0.304). Univariate logistical regression analysis found no association between slow-transit constipation and gastroparesis (OR 1.38, 95% CI 0.80-2.38, p=0.245) nor dyssynergic defecation and gastroparesis (OR 0.88, 95% CI 0.29-2.70, p=0.822). However, when stratifying gastroparesis based on severity, slow-transit constipation was found to be associated with severe gastroparesis (OR 2.45, 95% CI 1.20-5.00, p=0.014). This association was strengthened with the exclusion of patients with diabetes mellitus (OR 3.5, 95% CI 1.39-8.83, p=0.008) - a potential confounder.CONCLUSIONS & INFERENCES: Patients with severe gastroparesis (>35% gastric retention at the 4-hour mark on solid-phase GES) have an increased likelihood of having underlying slow-transit constipation. Dyssynergic defecation does not appear to be associated with gastroparesis (of any severity).

    View details for DOI 10.1111/nmo.14045

    View details for PubMedID 33231369

  • Patient Reported Outcomes and Objective Swallowing Assessments in a Multidisciplinary Dysphagia Clinic. The Laryngoscope Dewan, K., Clarke, J. O., Kamal, A. N., Nandwani, M., Starmer, H. M. 2020


    OBJECTIVES/HYPOTHESIS: Dysphagia encompasses a complex compilation of symptoms which often differ from findings of objective swallowing evaluations. The purpose of this investigation was to compare the results of subjective dysphagia measures to objective measures of swallowing in patients evaluated in a multidisciplinary dysphagia clinic.STUDY DESIGN: Prospective cohort study.METHODS: The study cohort included all patients evaluated in the multidisciplinary dysphagia clinic over 24months. Participants were evaluated by a multidisciplinary team including a laryngologist, gastroenterologist, and speech-language pathologist. Evaluation included a videofluoroscopic swallowing study (VFSS), fiberoptic endoscopic evaluation of swallowing (FEES), and transnasal esophagoscopy (TNE). Data collected included diet (FOIS), Eating Assessment Tool (EAT-10) score, Reflux symptom index (RSI) score, and the findings of the VFSS exam.RESULTS: A total of 75 patients were included in the analysis. The average EAT-10 score was 16.3±2.1, RSI was 21.4±0.6, and FOIS score was 6.0±1.33. VFSS revealed impairments in the oral phase in 40% of the cohort, pharyngeal in 59%, and esophageal in 49%. Abnormalities were noted in one phase for 32%, in 2 phases in 32%, and three phases in 18%. Patients with abnormal pharyngeal findings on VFSS had significantly higher EAT-10 scores (P = .04). Patients with abnormal oral findings on VFSS were noted to have significantly lower FOIS scores (P = .03).CONCLUSIONS: Data presented here demonstrate a relationship between patient reported symptoms and objective VFSS findings in a cohort of patients referred for multidisciplinary swallowing assessment suggesting such surveys are helpful screening tools but inadequate to fully characterize swallowing impairment.LEVEL OF EVIDENCE: 3 Laryngoscope, 2020.

    View details for DOI 10.1002/lary.29194

    View details for PubMedID 33103765

  • Type II Achalasia Is Increasing in Prevalence. Digestive diseases and sciences Zhou, M. J., Kamal, A., Freedberg, D. E., Markowitz, D., Clarke, J. O., Jodorkovsky, D. 2020


    BACKGROUND: Three manometric subtypes of achalasia were defined in the Chicago Classification approximately 10years ago: type I (aperistalsis), type II (pan-pressurization), and type III (spastic). Since the widespread use of this classification scheme, the evolving prevalence of these subtypes has not been elucidated. We aim to determine the prevalence of each subtype a decade after the adoption of the Chicago Classification.METHODS: This is a retrospective cohort analysis of patients diagnosed with achalasia on high-resolution manometry (HRM) at two major academic medical centers between 2015 and 2018. Patients were excluded if they had a diagnosis of another esophageal motility disorder, previously treated achalasia, or foregut surgery. Demographic data, manometric subtype, and esophageal dilatation grade on endoscopy were obtained. Prevalence of achalasia subtypes was compared with a published historical control population (2004-2007). Fischer's exact and t tests were used for analysis.RESULTS: Of 147 patients in the contemporary cohort and 99 in the historical control cohort, the prevalence of type I achalasia was 8% versus 21%, type II 63% versus 50%, and type III 29% versus 29%, respectively (p=0.01). The mean age in our population was 58years compared to 57years in the historical control, and the proportion of men 48% versus 47%, respectively (p=0.78). Mean endoscopic dilatation grade in the contemporary cohort was 1.5 for type I patients, 0.9 for type II, and 0.4 for type III, compared with 1.5, 0.6, and 0.4, respectively. Overall mean dilatation grade was 0.8 in our cohort versus 0.7 in the historical control (p=0.58).CONCLUSION: The prevalence of type II achalasia was significantly greater and prevalence of type I significantly less in our patient population compared to our predefined historical control. Other characteristics such as age and sex did not appear to contribute to these differences. Histopathological evidence has suggested that type II achalasia may be an earlier form of type I; thus, the increased prevalence of type II achalasia may be related to earlier detection of the disease. The adoption of HRM, widespread use of the Chicago Classification, and increased disease awareness in the past decade may be contributing to these changes in epidemiology.

    View details for DOI 10.1007/s10620-020-06668-7

    View details for PubMedID 33089487

  • Assessment of Gastric Emptying Times Between Pediatrics and Adults With Cyclic Vomiting Syndrome JOURNAL OF CLINICAL GASTROENTEROLOGY Kamal, A., Sarvepalli, S., Selvakumar, P., Lopez, R., Radhakrishnan, K., Gabbard, S. 2020; 54 (9): E89–E92


    Cyclic vomiting syndrome (CVS) is characterized by episodes of nausea and vomiting separated by symptom-free intervals. Rome IV guidelines have now distinguished CVS from other disorders such as cannabinoid hyperemesis. The pathogenesis of CVS, however, is poorly understood. Limited data exist on gastric emptying (GE) in patients with CVS. Therefore, the authors aim to measure the GE profile in pediatrics and adults with CVS.Patients with the diagnosis of CVS (per NASPGHAN and Rome IV) between December 1998 and March 2017 who underwent gastric emptying study (GES) and without documented cannabis use were included. Clinical features including demographics, medication use, and comorbidities were also recorded. Frequency of rapid, normal, and delayed emptying was reported, and multinomial univariate logistic regression was used to identify factors associated with each type of emptying.Sixty-seven subjects were included (50.7% female individuals, pediatrics n=15, adults n=52). At 2-hour retention, 40% of pediatric patients met criteria for rapid, 33.3% for normal, and 26.7% for delayed GE. In adults, 50% met criteria for rapid, 46.2% for normal, and 3.8% for delayed GE. For every 5-year increase in age, odds of rapid emptying on GES increased.(1) GE is predominantly rapid at 2 hours in pediatrics and adults with CVS. (2) Rapid GE seems to increase with age. (3) Current guidelines do not recommend GE in the initial management, however, further studies may play a role to help differentiate CVS from other functional gastric disorders.

    View details for DOI 10.1097/MCG.0000000000001352

    View details for Web of Science ID 000576509400003

    View details for PubMedID 32569030

  • The Role of Symptom Association Analysis in Gastroesophageal Reflux Testing. The American journal of gastroenterology Kamal, A. N., Clarke, J. O., Oors, J. M., Smout, A. J., Bredenoord, A. J. 2020


    Gastroesophageal reflux disease is characterized by the reflux of gastric contents into the esophagus with an estimated worldwide prevalence of 8%-33%. The current paradigm in gastroesophageal reflux disease diagnosis relies on recognition of symptoms and/or the presence of mucosal disease at the time of esophagogastroduodenoscopy. Recognition of symptoms, however, can arise with challenges, particularly when patients complain of less typical symptoms. Since first reported in 1969 by Spencer et al., the application of prolonged intraesophageal pH monitoring to identify pathologic reflux has evolved considerably. Utility of pH monitoring aims to investigate the degree of acid burden and frequency of reflux episode, and the relationship between symptoms and acid reflux events. This relationship is represented by either the Symptom Index, Symptom Sensitivity Index, Symptom Association Probability, or Ghillebert Probability Estimate. This article reviews symptom-association analysis during esophageal reflux testing, covering the literature on current methods of reflux testing, interpretation of symptom association, and practical issues that can arise during symptom analysis.

    View details for DOI 10.14309/ajg.0000000000000754

    View details for PubMedID 32740077

  • Mucosal impedance for esophageal disease: evaluating the evidence. Annals of the New York Academy of Sciences Clarke, J. O., Ahuja, N. K., Chan, W. W., Gyawali, C. P., Horsley-Silva, J. L., Kamal, A. N., Vela, M. F., Xiao, Y. 2020


    Impedance has traditionally been employed in esophageal disease as a means to assess bolus flow and reflux episodes. Recent and ongoing research has provided new and novel applications for this technology. Measurement of esophageal mucosal impedance, via either multichannel intraluminal impedance catheters or specially designed endoscopically deployed impedance catheters, provides a marker of mucosal integrity. Mucosal impedance has been shown to segregate gastroesophageal reflux disease (GERD) and eosinophilic esophagitis from non-GERD controls and may play a role in predicting response to reflux intervention. More data are needed with regard to other esophageal subgroups, outcome studies, and functional disease. Our paper reviews the history of impedance in esophageal disease, the means of assessing baseline and mucosal impedance, data with regard to the newly developed mucosal impedance probes, the clinical utility of mucosal impedance in specific clinical conditions, and limitations in our existing knowledge, along with suggestions for future studies.

    View details for DOI 10.1111/nyas.14414

    View details for PubMedID 32588457

  • The role of ambulatory 24-hour esophageal manometry in clinical practice. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society Kamal, A. N., Clarke, J. O., Oors, J. M., Bredenoord, A. J. 2020: e13861


    High-resolution manometry revolutionized the assessment of esophageal motility disorders and upgraded the classification through the Chicago Classification. A known disadvantage of standard HRM, however, is the inability to record esophageal motility function for an extended time interval; therefore, it represents only a more snapshot view of esophageal motor function. In contrast, ambulatory esophageal manometry measures esophageal motility over a prolonged period and detects motor activity during the entire circadian cycle. Furthermore, ambulatory manometry has the ability to measure temporal correlations between symptoms and motor events. This article aimed to review the clinical implications of ambulatory esophageal manometry for various symptoms, covering literature on the manometry catheter, interpretation of findings, and relevance in clinical practice specific to the evaluation of non-cardiac chest pain, chronic cough, and rumination syndrome.

    View details for DOI 10.1111/nmo.13861

    View details for PubMedID 32391594

  • Long-term outcomes of per-oral endoscopic myotomy compared to laparoscopic Heller myotomy for achalasia: a single-center experience. Surgical endoscopy Podboy, A. J., Hwang, J. H., Rivas, H., Azagury, D., Hawn, M., Lau, J., Kamal, A., Friedland, S., Triadafilopoulos, G., Zikos, T., Clarke, J. O. 2020


    INTRODUCTION: Many centers have reported excellent short-term efficacy of per-oral endoscopic myotomy (POEM) for the treatment of achalasia. However, long-term data are limited and there are few studies comparing the efficacy of POEM versus Heller Myotomy (HM).AIMS: To compare the long-term clinical efficacy of POEM versus HM.METHODS: Using a retrospective, parallel cohort design, all cases of POEM or HM for achalasia between 2010 and 2015 were assessed. Clinical failure was defined as (a) Eckardt Score>3 for at least 4weeks, (b) achalasia-related hospitalization, or (c) repeat intervention. All index manometries were classified via Chicago Classification v3. Pre-procedural clinical, manometric, radiographic data, and procedural data were reviewed.RESULTS: 98 patients were identified (55 POEM, 43 Heller) with mean follow-up of 3.94years, and 5.44years, respectively. 83.7% of HM patients underwent associated anti-reflux wrap (Toupet or Dor). Baseline clinical, demographic, radiographic, and manometric data were similar between the groups. There was no statistical difference in overall long-term success (POEM 72.7%, HM 65.1% p=0.417, although higher rates of success were seen in Type III Achalasia in POEM vs Heller (53.3% vs 44.4%, p<0.05). Type III Achalasia was the only variable associated with failure on a univariate COX analysis and no covariants were identified on a multivariate Cox regression. There was no statistical difference in GERD symptoms, esophagitis, or major procedural complications.CONCLUSION: POEM and HM have similar long-term (4-year) efficacy with similar adverse event and reflux rates. POEM was associated with greater efficacy in Type III Achalasia.

    View details for DOI 10.1007/s00464-020-07450-6

    View details for PubMedID 32157405

  • Changes in high-resolution manometric diagnosis over time: implications for clinical decision-making. Diseases of the esophagus : official journal of the International Society for Diseases of the Esophagus Triadafilopoulos, G., Kamal, A., Zikos, T., Nguyen, L., Clarke, J. O. 2020


    Although High resolution esophageal manometry (HRM) is the gold standard to assess esophageal motility, little is known about the stability of the manometric diagnosis over time and its implications for management. To assess the stability and usefulness of repeat HRM in patients presenting with esophageal symptoms over time we performed this retrospective study of patients with esophageal symptoms. Medical records, questionnaires, and HRM tracing were independently reviewed using the Chicago classification. The primary objective was to assess the stability of the manometric diagnosis over time; secondary objective was its change (positive or negative). At least one repeat study was performed in 86 patients (36% women, ages 20-86, with mild to moderate symptoms), while 26 had a third procedure. Mean intervals between studies were 15±1.6months (for baseline v. first study) and 13±0.8months (for second to third study). Of the 27 patients initially with a normal study, 11 changed (five had esophago-gastric junction outflow obstruction [EGJOO], two diffuse esophageal spasm [DES], one jackhammer esophagus [JE], and three ineffective esophageal motility [IEM] [41% change]). Of the 24 patients with initial EGJOO, only nine retained it (65.2% change). Of nine patients with initial DES, four changed (44.4% change). Similarly, different diagnosis was seen in 7 of 24 initial IEM patients (22.7% change). Only one patient had achalasia initially and this remained stable. Additional changes were noted on a third HRM. Fluidity in the HRM diagnosis over time questions its validity at any timepoint and raises doubts about the need for intervention.

    View details for DOI 10.1093/dote/doz094

    View details for PubMedID 31909786

  • Development of a Preliminary Question Prompt List as a Communication Tool for Adults With Gastroesophageal Reflux Disease: A Modified Delphi Study. Journal of clinical gastroenterology Kamal, A. n., Katzka, D. A., Achkar, E. n., Carlson, D. n., Clarke, J. n., Fass, R. n., Gyawali, C. P., Patel, D. n., Penagini, R. n., Rezaie, A. n., Roman, S. n., Savarino, E. n., Shaheen, N. J., Triadafilopoulos, G. n. 2020


    Question prompt lists (QPLs) are structured sets of disease-specific questions intended for patient use, encouraging patients to ask questions to facilitate their consultation with their physician.The aim of this study was to develop a QPL specific to adults with gastroesophageal reflux disease (GERD), created by esophageal experts.The QPL content (78 questions) was derived through a modified Delphi method consisting of 2 rounds. In round 1, 18 esophageal experts provided 5 answers to the prompt "What you wish your patients would ask" and "What questions do patients often not ask, that I wish they would ask?" In round 2, the experts rated each question on a 5-point Likert scale, and responses rated as "essential" or "important," determined by an a priori threshold of ≥4.0, were accepted for the QPL.Twelve esophageal experts participated. Of 143 questions from round 1, 110 (76.9%) were accepted for inclusion in the QPL, meeting a median value of ≥4.0, and, subsequently, it reduced to 78, minimizing redundancy. Median values ranged between 4.0 and 5.0, with the highest agreement median (5.0) for questions asking dosing and timing of proton pump inhibitor therapy, and surveillance in Barrett's. Questions were categorized into the following categories: "What does this illness mean," "lifestyle modifications," "general treatment," "treatment with proton pump inhibitors," "What I should expect for my future," and "Barrett's." The largest number of questions covered lifestyle modifications (21.8%), with the highest agreement median (5.0) for "How helpful are lifestyle modifications in GERD?"A preliminary GERD-specific QPL, the first of its kind, was developed by esophageal experts. Modification after more patient consultation and feedback is planned in subsequent versions to create a GERD-QPL for eventual use in clinical gastroenterology.

    View details for DOI 10.1097/MCG.0000000000001300

    View details for PubMedID 31985713

  • Building an integrated multidisciplinary swallowing disorder clinic: considerations, challenges, and opportunities. Annals of the New York Academy of Sciences Starmer, H. M., Dewan, K. n., Kamal, A. n., Khan, A. n., Maclean, J. n., Randall, D. R. 2020


    Dysphagia is a complex condition with numerous causes, symptoms, and treatments. As such, patients with dysphagia commonly require a multidisciplinary approach to their evaluation and treatment. Integrated multidisciplinary clinics provide an optimal format for a collaborative approach to patient care. In this manuscript, we will discuss considerations for teams looking to build a multidisciplinary dysphagia clinic, including what professionals are typically involved, what patients benefit most from this approach, what tests are most appropriate for which symptoms, financial issues, and traversing interpersonal challenges.

    View details for DOI 10.1111/nyas.14435

    View details for PubMedID 32686095

  • The functional lumen imaging probe in gastrointestinal disorders: the past, present, and future. Annals of the New York Academy of Sciences Clarke, J. O., Ahuja, N. K., Fernandez-Becker, N. Q., Gregersen, H. n., Kamal, A. N., Khan, A. n., Lynch, K. L., Vela, M. F. 2020


    The functional lumen imaging probe (FLIP) is a diagnostic tool that utilizes impedance planimetry to allow the assessment of luminal diameter and distensibility. It has been used primarily in esophageal diseases, in particular, in the assessment of achalasia, esophagogastric junction outflow obstruction, and eosinophilic esophagitis (EoE). The usage and publications have increased over the past decade and it is now an essential tool in the armamentarium of the esophagologist. Indications are emerging outside of the esophagus, in particular with regard to gastroparesis. Our paper will review the history of FLIP, optimal current usage, data for key esophageal disorders (including achalasia, reflux, and EoE), data for nonesophageal disorders, and our sense as to whether FLIP is ready for prime time, as well as gaps in evidence and suggestions for future research.

    View details for DOI 10.1111/nyas.14463

    View details for PubMedID 32814368

  • Diagnosis of gastroesophageal reflux: an update on current and emerging modalities. Annals of the New York Academy of Sciences Ang, D. n., Lee, Y. Y., Clarke, J. O., Lynch, K. n., Guillaume, A. n., Onyimba, F. n., Kamal, A. n., Gyawali, C. P. 2020


    Gastroesophageal reflux disease (GERD) is a common condition characterized by troublesome symptoms or esophageal mucosal lesions attributed to excessive esophageal acid exposure. Various pathophysiological mechanisms account for GERD, including impaired esophageal peristalsis and anatomical or physiological defects at the esophagogastric junction (EGJ). Endoscopy identifies GERD complications and detects potential alternative diagnoses. However, if symptoms persist despite proton pump inhibitor therapy, functional esophageal tests are useful to characterize reflux burden and define the symptom association profile. Ambulatory pH or pH-impedance monitoring measures the 24-h acid exposure time, which remains the most reproducible reflux metric and predicts response to antireflux therapy. Apart from identifying peristaltic dysfunction, esophageal high-resolution manometry defines the morphology and contractile vigor (EGJ-CI) of the EGJ. Novel metrics obtained from pH-impedance monitoring include the postreflux swallow-induced peristaltic wave index and mean nocturnal baseline impedance, which augment the diagnostic value of pH-impedance testing. Mucosal impedance can also be recorded using a probe inserted through a gastroscope, or a novel balloon catheter with arrays of impedance electrodes inserted following sedated endoscopy. The latest developments in functional esophageal tests define the GERD phenotype based on pathogenesis, reflux exposure, structural or motility disorders, and symptom burden, facilitating appropriate treatment.

    View details for DOI 10.1111/nyas.14369

    View details for PubMedID 32428279

  • Baseline impedance via manometry and ambulatory reflux testing are not equivalent when utilized in the evaluation of potential extra-esophageal gastroesophageal reflux disease. Journal of thoracic disease Zikos, T. A., Triadafilopoulos, G. n., Kamal, A. n., Podboy, A. n., Sonu, I. S., Regalia, K. A., Nandwani, M. C., Nguyen, L. A., Fernandez-Becker, N. Q., Clarke, J. O. 2020; 12 (10): 5628–38


    Esophageal baseline impedance (BI) shows promise for the diagnosis of gastroesophageal reflux disease (GERD), but means of acquisition and relevance to extra-esophageal manifestations of GERD (EE-GERD) remain unclear. In this study we aim to (I) evaluate concordance between BI as measured by 24-hour pH-impedance (pH-MII) and high-resolution impedance manometry (HRIM), and (II) assess relationship to potential EE-GERD symptoms.In this prospective open cohort study, patients presenting for outpatient HRIM and pH-MII studies were prospectively enrolled. All patients completed the GERD-HRQL, NOSE, and respiratory symptom index questionnaire (RSI), plus questions regarding wheezing and dental procedures. HRIM and pH-MII were evaluated with calculation of BI. Correlations were assessed using either Pearson's correlation or Spearman's rank coefficients.70 HRIM patients were enrolled, 35 of whom underwent pH-MII. There was no correlation between BI measurements as assessed by HRIM and pH-MII proximally, but there was moderate-weak correlation distally (r=0.34 to 0.5). Distal acid exposure time correlated with distal BI only for measurements by pH-MII (rho= -0.5 to -0.65), and not by HRIM. There was no relationship between proximal acid exposure time and proximal BI. There were no correlations when comparing proximal or distal BI measurements, acid exposure times, and impedance events to symptoms.Concordance between BI as measured by HRIM and pH-MII is poor, especially proximally, suggesting that these two methods are not interchangeable. There is no correlation between BI both distally/proximally and symptoms of either GERD/EE-GERD, suggesting that many symptoms are unrelated to acid or that BI is not an adequate marker to assess EE-GERD symptoms.

    View details for DOI 10.21037/jtd-20-1623

    View details for PubMedID 33209395

    View details for PubMedCentralID PMC7656325

  • Reflux Hypersensitivity: How to Approach Diagnosis and Management. Current gastroenterology reports Aggarwal, P. n., Kamal, A. N. 2020; 22 (9): 42


    This paper aims to review the definition and diagnostic criteria for reflux hypersensitivity and comment on the present and future management of this condition.In 2016, the Rome IV criteria redefined reflux hypersensitivity as characterized by typical reflux symptoms, absence of endoscopic mucosal disease, absence of pathologic gastroesophageal reflux, and positive symptom correlation between reflux and heartburn episodes. Though uncertain, TPRV1 receptors have been implicated in the pathophysiology of reflux hypersensitivity. Recent studies have shown neuromodulators like SSRIs, SNRIs, and TCAs may be the future of managing this condition. With the release of the Rome IV criteria and availability of continuous pH monitoring, the diagnosis of reflux hypersensitivity has become more streamlined. Though there is no definitive therapy for reflux hypersensitivity, several anti-secretory agents and neuromodulators have shown some efficacy in therapeutic trials. The lack of large-scale, randomized controlled trials, however, reinforces the need for further research into the pharmacotherapy of reflux hypersensitivity.

    View details for DOI 10.1007/s11894-020-00779-x

    View details for PubMedID 32651667

  • The Association Between Gastroparesis and Slow Transit Constipation as Seen by Wireless Motility Capsule (WMC) Radetic, M., Kamal, A., Rouphael, C., Cline, M. LIPPINCOTT WILLIAMS & WILKINS. 2019: S692–S693
  • Gastric per-oral endoscopic myotomy: Current status and future directions WORLD JOURNAL OF GASTROENTEROLOGY Podboy, A., Hwang, J., Nguyen, L. A., Garcia, P., Zikos, T. A., Kamal, A., Triadafilopoulos, G., Clarke, J. O. 2019; 25 (21): 2581–90
  • Under Pressure: Do Volume-Based Measurements Define Rectal Hyposensitivity in Clinical Practice? DIGESTIVE DISEASES AND SCIENCES Kamal, A. N., Garcia, P., Clarke, J. O. 2019; 64 (5): 1062–63
  • Under Pressure: Do Volume-Based Measurements Define Rectal Hyposensitivity in Clinical Practice? Digestive diseases and sciences Kamal, A. N., Garcia, P., Clarke, J. O. 2019

    View details for PubMedID 30963367

  • High Prevalence of Slow Transit Constipation in Patients With Gastroparesis JOURNAL OF NEUROGASTROENTEROLOGY AND MOTILITY Zikos, T. A., Kamal, A. N., Neshatian, L., Triadafilopoulos, G., Clarke, J. O., Nandwani, M., Nguyen, L. A. 2019; 25 (2): 267–75

    View details for DOI 10.5056/jnm18206

    View details for Web of Science ID 000464525700012

  • High Prevalence of Slow Transit Constipation in Patients With Gastroparesis. Journal of neurogastroenterology and motility Zikos, T. A., Kamal, A. N., Neshatian, L., Triadafilopoulos, G., Clarke, J. O., Nandwani, M., Nguyen, L. A. 2019


    Background/Aims: Current evidence suggests the presence of motility or functional abnormalities in one area of the gastrointestinal tract increases the likelihood of abnormalities in others. However, the relationship of gastroparesis to chronic constipation (slow transit constipation and dyssynergic defecation) has been incompletely evaluated.Methods: We retrospectively reviewed the records of all patients with chronic dyspeptic symptoms and constipation who underwent both a solid gastric emptying scintigraphy and a highresolution anorectal manometry at our institution since January 2012. When available, Xray defecography and radiopaque marker colonic transit studies were also reviewed. Based on the gastric emptying results, patients were classified as gastroparesis or dyspepsia with normal gastric emptying (control group). Differences in anorectal and colonic findings were then compared between groups.Results: Two hundred and six patients met the inclusion criteria. Patients with gastroparesis had higher prevalence of slow transit constipation by radiopaque marker study compared to those with normal emptying (64.7% vs 28.1%, P = 0.013). Additionally, patients with gastroparesis had higher rates of rectocele (88.9% vs 60.0%, P = 0.008) and intussusception (44.4% vs 12.0%, P = 0.001) compared to patients with normal emptying. There was no difference in the rate of dyssynergic defecation between those with gastroparesis vs normal emptying (41.1% vs 42.1%, P = 0.880), and no differences in anorectal manometry findings.Conclusions: Patients with gastroparesis had a higher rate of slow transit constipation, but equal rates of dyssynergic defecation compared to patients with normal gastric emptying. These findings argue for investigation of possible delayed colonic transit in patients with gastroparesis and vice versa.

    View details for PubMedID 30870880

  • Gastric per-oral endoscopic myotomy: Current status and future directions. World journal of gastroenterology Podboy, A. n., Hwang, J. H., Nguyen, L. A., Garcia, P. n., Zikos, T. A., Kamal, A. n., Triadafilopoulos, G. n., Clarke, J. O. 2019; 25 (21): 2581–90


    Gastroparesis, or symptomatic delayed gastric emptying in the absence of mechanical obstruction, is a challenging and increasingly identified syndrome. Medical options are limited and the only medication approved by the Food and Drug Administration for treatment of gastroparesis is metoclopramide, although other agents are frequently used off label. With this caveat, first-line treatments for gastroparesis include dietary modifications, antiemetics and promotility agents, although these therapies are limited by suboptimal efficacy and significant medication side effects. Treatment of patients that fail first-line treatments represents a significant therapeutic challenge. Recent advances in endoscopic techniques have led to the development of a promising novel endoscopic therapy for gastroparesis via endoscopic pyloromyotomy, also referred to as gastric per-oral endoscopic myotomy or per-oral endoscopic pyloromyotomy. The aim of this article is to review the technical aspects of the per-oral endoscopic myotomy procedure for the treatment of gastroparesis, provide an overview of the currently published literature, and outline potential next directions for the field.

    View details for DOI 10.3748/wjg.v25.i21.2581

    View details for PubMedID 31210711

    View details for PubMedCentralID PMC6558440

  • Inflammatory Bowel Disease and Irritable Bowel Syndrome: What to Do When There Is an Overlap INFLAMMATORY BOWEL DISEASES Kamal, A., Padival, R., Lashner, B. 2018; 24 (12): 2479–82

    View details for DOI 10.1093/ibd/izy277

    View details for Web of Science ID 000456677100001

    View details for PubMedID 30169572