ObjectiveWe conducted a nationwide survey using a validated Gastrointestinal Health Questionnaire (GHQ) for Rett syndrome (RTT) to provide an updated and accurate baseline assessment of the prevalence of common gastrointestinal (GI) issues in RTT, based on parental reporting.MethodsParents and caregivers of females with RTT or normally developing, unaffected, age‐matched controls completed the GHQ survey. The prevalence of GI symptoms and personality and mood symptoms due to stomach or intestinal problems, as well as GI medication usage and surgical interventions, were assessed in females with RTT and unaffected controls. The relation between GI symptoms and medication usage, surgical status, age, and genetic mutation were analyzed.ResultsParents of 118 females with RTT and 27 unaffected females completed the GHQ. GI symptoms were common in females with RTT, including constipation (81%), gas and bloating (70%), issues with eating, chewing and swallowing (73%), and irritability because of stomach or intestinal problems (53%). Females with RTT commonly used proton pump inhibitors (52%) and laxatives (64%). Medication usage was associated with significantly higher GHQ symptom scores. Parents of individuals with RTT reported a significantly higher prevalence of GI symptoms affecting their daughters in all symptom categories compared with unaffected females.ConclusionsGI problems are common in RTT and pose a significant medical burden to caregivers. The GHQ is a useful tool to assess GI issues in individuals with RTT. Improved recognition of these issues may allow for improved treatment and enhanced quality of life for girls and women affected by RTT.