Association between eating disorders and functional gastrointestinal disorders: a systematic review

Introduction: Functional gastrointestinal disorders (FGIDs) and eating disorders (EDs) frequently coexist with one another. It is not unusual for a patient to present with both diseases because they share many similarities with reference to the deeper psychological factors and the connection between the gastrointestinal tract and the brain. Many studies have shown that while the occurrence of FGID in eating disorder patients is noteworthy, it varies greatly, mostly due to disparate research approaches. This review aims to synthesize 2015-2025 evidence on ED-FGID associations, prevalence patterns, bidirectionality, shared psychological mechanisms, and implications for screening and multidisciplinary management. Methods: In line with the PRISMA statement, this systematic review retrieved English-language research published within the period of 2015-2025 using a range of databases for studies related to the relationship between EDs and FGIDs. The quality of the observational studies with eligibility criteria met for data retrieval has been appraised using National Institutes of Health standards. The data has been narratively reported instead of meta-analyzed. Results: The criteria are met in nine studies published between 2016 and 2025. The studies include both the cross-sectional type and the cohort type. The overall quality of the studies leans towards being sound. The trend indicates that the co-occurrence between EDs and FGIDs is prominent, with irritable bowel syndrome being most prevalent. The two-way connection between disordered eating and GI symptoms is apparent. The impact of dietary practices, in addition to the psychological underpinning of both anxiety and depression, makes a compelling argument about the relevance of routinely screening patients with FGIDs about eating disorders. Conclusion: The reviewed article emphasizes a close link between EDs and FGIDs in terms of brain-gut overlap, wherein symptoms and eating habits mutually interact and reinforce each other. These findings underscore the importance of routine screening for eating disorders in individuals presenting with FGIDs to improve early identification and multidisciplinary management.