Bio


Patricia Garcia, MD is a board certified gastroenterologist and clinical informaticist. She is fellowship trained in neurogastroenterology and specializes in treating disorders of gastrointestinal motility including trouble swallowing, heartburn, reflux, constipation, fecal incontinence and pelvic floor dysfunction. She is also passionate about using digital health technologies and artificial intelligence to improve physician burden and patient care.

Clinical Focus


  • Gastroenterology
  • Neurogastroenterology and Motility
  • Medical Informatics

Academic Appointments


Administrative Appointments


  • Associate Chief Medical Information Officer, Ambulatory Care, Stanford Health Care (2022 - Present)
  • Director, GI Motility Laboratory, Stanford Digestive Health Center (2018 - Present)

Boards, Advisory Committees, Professional Organizations


  • Member, American Neurogastroenterolgy and Motility Society (2014 - Present)
  • Member, American Gastroenterology Association (2011 - Present)
  • Member, American College of Gastroenterology (2011 - Present)

Professional Education


  • Board Certification, American Board of Preventive Medicine, Clinical Informatics (2024)
  • Fellowship, Johns Hopkins University, Neurogastroenterology and Motility (2015)
  • Board Certification: American Board of Internal Medicine, Gastroenterology (2014)
  • Fellowship: New York Presbyterian Hospital of Columbia and Cornell Universities (2014) NY
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2011)
  • Residency: University of Pennsylvania Health System (2011) PA
  • Medical Education: University of Michigan Medical School (2008) MI

All Publications


  • Use of a footstool improves rectal balloon expulsion in some patients with defecatory disorders. Neurogastroenterology and motility Ulsh, L., Halawi, H., Triadafilopoulos, G., Gurland, B., Nguyen, L., Garcia, P., Sonu, I., Fernandez-Becker, N., Becker, L., Sheth, V., Neshatian, L. 2024: e14781

    Abstract

    Whether patients with defecatory disorders (DDs) with favorable response to a footstool have distinctive anorectal pressure characteristics is unknown. We aimed to identify the clinical phenotype and anorectal pressure profile of patients with DDs who benefit from a footstool.This is a retrospective review of patients with high resolution anorectal manometry (HR-ARM) and balloon expulsion test (BET) from a tertiary referral center. BET was repeated with a 7-inch-high footstool in those who failed it after 120 s. Data were compared among groups with respect to BET results.Of the 667 patients with DDs, a total of 251 (38%) had failed BET. A footstool corrected BET in 41 (16%) of those with failed BET. Gender-specific differences were noted in anorectal pressures, among patients with and without normal BET, revealing gender-based nuances in pathophysiology of DDs. Comparing patients who passed BET with footstool with those who did not, the presence of optimal stool consistency, with reduced instances of loose stools and decreased reliance on laxatives were significant. Additionally, in women who benefited from a footstool, lower anal pressures at rest and simulated defecation were observed. Independent factors associated with a successful BET with a footstool in women included age <50, Bristol 3 or 4 stool consistency, lower anal resting pressure and higher rectoanal pressure gradient.Identification of distinctive clinical and anorectal phenotype of patients who benefited from a footstool could provide insight into the factors influencing the efficacy of footstool utilization and allow for an individualized treatment approach in patients with DDs.

    View details for DOI 10.1111/nmo.14781

    View details for PubMedID 38488172

  • Artificial Intelligence-Generated Draft Replies to Patient Inbox Messages. JAMA network open Garcia, P., Ma, S. P., Shah, S., Smith, M., Jeong, Y., Devon-Sand, A., Tai-Seale, M., Takazawa, K., Clutter, D., Vogt, K., Lugtu, C., Rojo, M., Lin, S., Shanafelt, T., Pfeffer, M. A., Sharp, C. 2024; 7 (3): e243201

    Abstract

    The emergence and promise of generative artificial intelligence (AI) represent a turning point for health care. Rigorous evaluation of generative AI deployment in clinical practice is needed to inform strategic decision-making.To evaluate the implementation of a large language model used to draft responses to patient messages in the electronic inbox.A 5-week, prospective, single-group quality improvement study was conducted from July 10 through August 13, 2023, at a single academic medical center (Stanford Health Care). All attending physicians, advanced practice practitioners, clinic nurses, and clinical pharmacists from the Divisions of Primary Care and Gastroenterology and Hepatology were enrolled in the pilot.Draft replies to patient portal messages generated by a Health Insurance Portability and Accountability Act-compliant electronic health record-integrated large language model.The primary outcome was AI-generated draft reply utilization as a percentage of total patient message replies. Secondary outcomes included changes in time measures and clinician experience as assessed by survey.A total of 197 clinicians were enrolled in the pilot; 35 clinicians who were prepilot beta users, out of office, or not tied to a specific ambulatory clinic were excluded, leaving 162 clinicians included in the analysis. The survey analysis cohort consisted of 73 participants (45.1%) who completed both the presurvey and postsurvey. In gastroenterology and hepatology, there were 58 physicians and APPs and 10 nurses. In primary care, there were 83 physicians and APPs, 4 nurses, and 8 clinical pharmacists. The mean AI-generated draft response utilization rate across clinicians was 20%. There was no change in reply action time, write time, or read time between the prepilot and pilot periods. There were statistically significant reductions in the 4-item physician task load score derivative (mean [SD], 61.31 [17.23] presurvey vs 47.26 [17.11] postsurvey; paired difference, -13.87; 95% CI, -17.38 to -9.50; P < .001) and work exhaustion scores (mean [SD], 1.95 [0.79] presurvey vs 1.62 [0.68] postsurvey; paired difference, -0.33; 95% CI, -0.50 to -0.17; P < .001).In this quality improvement study of an early implementation of generative AI, there was notable adoption, usability, and improvement in assessments of burden and burnout. There was no improvement in time. Further code-to-bedside testing is needed to guide future development and organizational strategy.

    View details for DOI 10.1001/jamanetworkopen.2024.3201

    View details for PubMedID 38506805

  • The association between vitamin-D deficiency and fecal incontinence. Neurogastroenterology and motility Neshatian, L., Grant, G., Fernandez-Becker, N., Yuan, Y., Garcia, P., Becker, L., Gurland, B., Triadafilopoulos, G. 2024: e14753

    Abstract

    BACKGROUND: Vitamin-D is essential for musculoskeletal health. We aimed to determine whether patients with fecal incontinence (FI): (1) are more likely to have vitamin-D deficiency and, (2) have higher rates of comorbid medical conditions.METHODS: We examined 18- to 90-year-old subjects who had 25-hydroxy vitamin-D levels, and no vitamin-D supplementation within 3months of testing, in a large, single-institutional electronic health records dataset, between 2017 and 2022. Cox proportional hazards survival analysis was used to assess association of vitamin-D deficiency on FI.KEY RESULTS: Of 100,111 unique individuals tested for serum 25-hydroxy vitamin-D, 1205 (1.2%) had an established diagnosis of FI. Most patients with FI were female (75.9% vs. 68.7%, p=0.0255), Caucasian (66.3% vs. 52%, p=0.0001), and older (64.2 vs. 53.8, p<0.0001). Smoking (6.56% vs. 2.64%, p=0.0001) and GI comorbidities, including constipation (44.9% vs. 9.17%, p=0.0001), irritable bowel syndrome (20.91% vs. 3.72%, p=0.0001), and diarrhea (28.55% vs. 5.2%, p=0.0001) were more common among FI patients. Charlson Comorbidity Index score was significantly higher in patients with FI (5.5 vs. 2.7, p<0.0001). Significantly higher proportions of patients with FI had vitamin-D deficiency (7.14% vs. 4.45%, p<0.0001). Moreover, after propensity-score matching, rate of new FI diagnosis was higher in patients with vitamin-D deficiency; HR 1.9 (95% CI [1.14-3.15]), p=0.0131.CONCLUSION & INFERENCES: Patients with FI had higher rates of vitamin-D deficiency along with increased overall morbidity. Future research is needed to determine whether increased rate of FI in patients with vitamin-D deficiency is related to frailty associated with increased medical morbidities.

    View details for DOI 10.1111/nmo.14753

    View details for PubMedID 38316640

  • Ethical Implications of Artificial Intelligence in Gastroenterology. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association Aggarwal, N., Singh, A., Garcia, P., Guha, S. 2024

    View details for DOI 10.1016/j.cgh.2024.01.017

    View details for PubMedID 38278198

  • Development and Validation of a Machine Learning System to Identify Reflux Events in Esophageal 24-hour pH/Impedance Studies. Clinical and translational gastroenterology Zhou, M. J., Zikos, T., Goel, K., Goel, K., Gu, A., Re, C., Rodriguez, D., Clarke, J. O., Garcia, P., Fernandez-Becker, N., Sonu, I., Kamal, A., Sinha, S. R. 2023

    Abstract

    INTRODUCTION: Esophageal 24-hour pH/impedance testing is routinely performed to diagnose gastroesophageal reflux disease (GERD). Interpretation of these studies is time-intensive for expert physicians and has high inter-reader variability. There are no commercially available machine learning tools to assist with automated identification of reflux events in these studies.METHODS: A machine learning system to identify reflux events in 24-hour pH/impedance studies was developed, which included an initial signal processing step and a machine learning model. Gold standard reflux events were defined by a group of expert physicians. Performance metrics were computed to compare the machine learning system, current automated detection software (Reflux Reader v6.1), and an expert physician reader.RESULTS: The study cohort included 45 patients (20/5/20 patients in the training/validation/test sets, respectively). Mean age was 51 (standard deviation [SD] 14.5) years, 47% of patients were male, and 78% of studies were performed off proton pump inhibitor (PPI). Comparing the machine learning system vs. current automated software vs. expert physician reader, AUC was 0.87 (95% CI 0.85-0.89) vs. 0.40 (95% CI 0.37-0.42) vs. 0.83 (95% CI 0.81-0.86), respectively; sensitivity was 68.7% vs. 61.1% vs. 79.4%, respectively; and specificity was 80.8% vs. 18.6% vs. 87.3%, respectively.DISCUSSION: We trained and validated a novel machine learning system to successfully identify reflux events in 24-hour pH/impedance studies. Our model performance was superior to that of existing software and comparable to that of a human reader. Machine learning tools could significantly improve automated interpretation of pH/impedance studies.

    View details for DOI 10.14309/ctg.0000000000000634

    View details for PubMedID 37578060

  • Differential Findings on Anorectal Manometry in Patients with Parkinson's Disease and Defecatory Dysfunction. Movement disorders clinical practice Zhou, W., Triadafilopoulos, G., Gurland, B., Halawi, H., Becker, L., Garcia, P., Nguyen, L., Miglis, M., Muppidi, S., Sinn, D. I., Jaradeh, S., Neshatian, L. 2023; 10 (7): 1074-1081

    Abstract

    Gastrointestinal dysfunction, particularly constipation, is among the most common non-motor manifestations in Parkinson's Disease (PD). We aimed to identify high-resolution anorectal manometry (HR-ARM) abnormalities in patients with PD using the London Classification.We conducted a retrospective review of all PD patients at our institution who underwent HR-ARM and balloon expulsion test (BET) for evaluation of constipation between 2015 and 2021. Using age and sex-specific normal values, HR-ARM recordings were re-analyzed and abnormalities were reported using the London Classification. A combination of Wilcoxon rank sum and Fisher's exact test were used.36 patients (19 women) with median age 71 (interquartile range [IQR]: 69-74) years, were included. Using the London Classification, 7 (19%) patients had anal hypotension, 17 (47%) had anal hypocontractility, and 3 women had combined hypotension and hypocontractility. Anal hypocontractility was significantly more common in women compared to men. Abnormal BET and dyssynergia were noted in 22 (61%) patients, while abnormal BET and poor propulsion were only seen in 2 (5%). Men had significantly more paradoxical anal contraction and higher residual anal pressures during simulated defecation, resulting in more negative recto-anal pressure gradients. Rectal hyposensitivity was seen in nearly one third of PD patients and comparable among men and women.Our data affirms the high prevalence of anorectal disorders in PD. Using the London Classification, abnormal expulsion and dyssynergia and anal hypocontractility were the most common findings in PD. Whether the high prevalence of anal hypocontractility in females is directly related to PD or other confounding factors will require further research.

    View details for DOI 10.1002/mdc3.13755

    View details for PubMedID 37476327

    View details for PubMedCentralID PMC10354598

  • Differential Findings on Anorectal Manometry in Patients with Parkinson's Disease and Defecatory Dysfunction MOVEMENT DISORDERS CLINICAL PRACTICE Zhou, W., Triadafilopoulos, G., Gurland, B., Halawi, H., Becker, L., Garcia, P., Nguyen, L., Miglis, M., Muppidi, S., Sinn, D., Jaradeh, S., Neshatian, L. 2023

    View details for DOI 10.1002/mdc3.13755

    View details for Web of Science ID 000982806800001

  • The Impact of Intermittent Fasting on Patients With Suspected Gastroesophageal Reflux Disease. Journal of clinical gastroenterology Jiang, Y., Sonu, I., Garcia, P., Fernandez-Becker, N. Q., Kamal, A. N., Zikos, T. A., Singh, S., Neshatian, L., Triadafilopoulos, G., Goodman, S. N., Clarke, J. O. 2022

    Abstract

    GOAL: The aim was to investigate the short-term impact of time restricted feeding on patients with suspected gastroesophageal reflux disease (GERD).BACKGROUND: Lifestyle modifications are often suggested, but the role of diet in GERD is unclear. Intermittent fasting is popular in the media and has demonstrated potential benefits with weight loss and inflammatory conditions as well as alterations in gastrointestinal hormones.STUDY: Patients who were referred for 96-hour ambulatory wireless pH monitoring off proton pump inhibitor to investigate GERD symptoms were screened for eligibility. Patients were instructed to maintain their baseline diet for the first 2 days of pH monitoring and switch to an intermittent fasting regimen (16 consecutive hour fast and 8h eating window) for the second 2 days. Objective measures of reflux and GERD symptom severity were collected and analyzed.RESULTS: A total of 25 participants were analyzed. 9/25 (36%) fully adhered to the intermittent fasting regimen, with 21/25 (84%) demonstrating at least partial compliance. Mean acid exposure time on fasting days was 3.5% versus 4.3% on nonfasting days. Intermittent fasting was associated with a 0.64 reduction in acid exposure time (95% CI: -2.32, 1.05). There was a reduction in GERD symptom scores of heartburn and regurgitation during periods of intermittent fasting (14.3 vs. 9.9; difference of -4.46, 95% CI: -7.6,-1.32).CONCLUSIONS: Initial adherence to time restricted eating may be difficult for patients. There is weak statistical evidence to suggest that intermittent fasting mildly reduces acid exposure. Our data show that short-term intermittent fasting improves symptoms of both regurgitation and heartburn.

    View details for DOI 10.1097/MCG.0000000000001788

    View details for PubMedID 36730832

  • Marijuana, Ondansetron, and Promethazine Are Perceived as Most Effective Treatments for Gastrointestinal Nausea. Digestive diseases and sciences Zikos, T. A., Nguyen, L., Kamal, A., Fernandez-Becker, N., Regalia, K., Nandwani, M., Sonu, I., Garcia, M., Okafor, P., Neshatian, L., Grewal, D., Garcia, P., Triadafilopoulos, G., Clarke, J. O. 2020

    Abstract

    BACKGROUND: Many anti-nausea treatments are available for chronic gastrointestinal syndromes, but data on efficacy and comparative effectiveness are sparse.AIMS: To conduct a sectional survey study of patients with chronic nausea to assess comparative effectiveness of commonly used anti-nausea treatments.METHODS: Outpatients at a single center presenting for gastroenterology evaluation were asked to rate anti-nausea efficacy on a scale of 0 (no efficacy) to 5 (very effective) of 29 commonly used anti-nausea treatments and provide other information about their symptoms. Additional information was collected from the patients' chart. The primary outcome was to determine which treatments were better or worse than average using a t test. The secondary outcome was to assess differential response by individual patient characteristics using multiple linear regression.RESULTS: One hundred and fifty-three patients completed the survey. The mean efficacy score of all anti-nausea treatments evaluated was 1.73. After adjustment, three treatments had scores statically higher than the mean, including marijuana (2.75, p<0.0001), ondansetron (2.64, p<0.0001), and promethazine (2.46, p<0.0001). Several treatments, including many neuromodulators, complementary and alternative treatments, erythromycin, and diphenhydramine had scores statistically below average. Patients with more severe nausea responded better to marijuana (p=0.036) and diphenhydramine (p<0.001) and less so to metoclopramide (p=0.020). There was otherwise no significant differential response by age, gender, nausea localization, underlying gastrointestinal cause of nausea, and GCSI.CONCLUSIONS: When treating nausea in patients with chronic gastrointestinal syndromes, clinicians may consider trying higher performing treatments first, and forgoing lower performing treatments. Further prospective research is needed, particularly with respect to highly effective treatments.

    View details for DOI 10.1007/s10620-020-06195-5

    View details for PubMedID 32185665

  • Recurrent Small Bowel Obstruction with Intraluminal Structures. The journal of trauma and acute care surgery Sun, B. J., Kopecky, K. E., Garcia, P. n., Spain, D. A. 2020

    View details for DOI 10.1097/TA.0000000000002956

    View details for PubMedID 33003015

  • 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
  • REFRACTORY GASTROPARESIS: GASTRIC PERORAL ENDOSCOPIC MYOTOMY (G-POEM) VS. INTRAPYLORIC BOTULINUM TOXIN INJECTION Parsa, N., Yang, J., Gutierrez, O., Moran, R., Sanaei, O., Fayad, L., Dbouk, M., Paiji, C., Kumbhari, V., Mullin, G., Stein, E. M., Abdi, T., Garcia, P., Kalloo, A. N., Canto, M. I., Clarke, J. O., Khashab, M. A. MOSBY-ELSEVIER. 2018: AB241–AB242