Background: Gastrointestinal (GI) disorders are highly prevalent, costly, and complex. Multidisciplinary gastrointestinal care (MGC), integrating medicine, nutrition, and behavioral health, is a best practice for managing GI needs, but access is limited by the availability of gastroenterologists and MGC clinics. Virtual MGC may bridge the gap, but it is unclear the extent to which patients engage in virtual MGC and the outcomes of virtual services delivered at scale. Objective: This study describes patient characteristics, engagement, and outcomes of a large-scale virtual MGC program and evaluates whether dietitian and behavioral health support mediates the association between medical engagement and symptom improvement. Methods: We conducted a retrospective cohort study of 11,345 adult patients receiving virtual MGC with gastroenterologists, GI-specialized advanced practice providers (APPs), registered dietitians, licensed psychologists, and care coordinators between April 2021 and August 2025. Patients completed virtual onboarding with a GI APP and medical, dietary, and behavioral interventions delivered through synchronous telehealth and asynchronous chat. Data were from web-based intake forms and electronic health records. Patient-reported outcomes included symptom control and symptom improvement (Yes/No). Descriptive analyses, logistic regression, and path analysis were conducted across 20 imputed datasets. Results: Virtual patients receiving MGC were 43.3 (SD 12.78) years on average, and 66.4% (7532/11,345) were female. Patients primarily presented with Disorders of Gut-Brain Interaction (4460/11,345, 39.3%) and Gastroesophageal Reflux Disease (2775/11,345, 24.5%). The median wait time for an initial appointment was 6 days (IQR 3-9). Patients had a median of 2 GI visits (IQR 1-3), 2 dietitian visits (IQR 1-3), and 1 behavioral health visit (IQR 0-2). As the number of visits increases, the odds of achieving positive outcomes increase significantly after controlling for age, sex, symptom severity at baseline, symptom frequency at baseline, and days in care. This translates to 92.39% with symptom improvement, 94.67% with symptom control, and 98.13% with no noticeable or mild symptoms among those with 4 or more appointments. Path analysis confirmed that GI APP engagement was significantly associated with increased dietitian and behavioral health usage, which was associated with symptom improvement. The direct pathway from GI APP engagement to symptom improvement was also significant. Conclusions: This innovative study demonstrates that a virtual-first MGC model is not only feasible at a national scale but is effective in achieving symptom control and improvement across a clinically diverse GI population. We provide evidence about successfully delivering high-quality care outside traditional clinical settings. This work distinguishes itself by analyzing the mechanisms of integrated care, specifically how medical engagement facilitates the use of specialized nutritional and behavioral interventions that are often inaccessible in community care. In the real world, this model offers a scalable solution to geographic specialist shortages, ensuring that best-practice care is available to patients regardless of their location or the local supply of specialists. Trial Registration:
Behavior change beyond intervention: an activity-theoretical perspective on human-centered design of personal health technology
IntroductionModern personal technologies, such as smartphone apps with artificial intelligence (AI) capabilities, have a significant potential for helping people make necessary changes in their behavior