Abstract Gastrointestinal (GI) illness interventions are increasingly utilizing eHealth technologies, yet little is currently known about the extent of their impact on patient outcomes. The purpose of this study was to conduct a meta-analysis of the GI eHealth intervention literature. We used a comprehensive search strategy to locate studies. To be included, studies had to be a randomized controlled trial comparing an eHealth intervention condition against a no-treatment or waitlist control condition. Studies had to report data on at least one of the following patient outcomes: medication adherence, quality of life (QoL), psychological distress, illness-related knowledge, or number of patient visits to the clinic/hospital. Analyses weighted effect sizes (d) by their inverse variance and combined them using random effects meta-analytic procedures. K = 19 studies conducted in eight countries with a cumulative sample size of N = 3,193 were meta-analyzed. Findings indicated that GI eHealth interventions improved patients’ QoL (d = .25, p = .008), psychological distress (d = .24, p = .017), medication adherence (d = .17, p = .014), and illness-related knowledge (d = .19, p = .002). GI eHealth interventions also significantly reduced the number of patient visits to the clinic/hospital (d = .78, p = .005). Our findings suggest that eHealth interventions hold promise in improving patient outcomes for those with GI illnesses. We suggest the next generation of GI interventions continue developing and evaluating the impact of technology using randomized controlled trial designs, and perhaps consider adapting existing efficacious interventions for burgeoning platforms, such as smartphones and tablets.