The intersect of gastrointestinal symptoms and malnutrition associated with anorexia nervosa and avoidant/restrictive food intake disorder: Functional or pathophysiologic?-A systematic review.

Objective: Although multiple pathophysiologic changes develop within the gastrointestinal (GI) system in the setting of malnutrition, the etiology of the reported multitude of symptoms in those with anorexia nervosa and avoidant restrictive intake disorder, as well as their contribution toward disordered eating, remain poorly understood. This systematic review seeks to better understand how these physiologic changes of malnutrition of the esophagus, stomach, intestines, and pancreas contribute toward the reported GI symptoms, as well as better understand how celiac disease, inflammatory bowel disease, pelvic floor dysfunction, and Ehlers-Danlos syndrome contribute toward disordered eating.

Methods: Studies of any design exploring the pathogenesis of complications and treatment strategies were included. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used to structure and complete the review.

Results: A total of 146 articles were used for the review. The majority of studies were observational or case reports/case series.

Discussion: Pathophysiologic changes of the esophagus, stomach, and intestines develop with malnutrition, although these changes do not consistently correlate with expressed GI symptoms in patients with restrictive eating disorders. Celiac disease and inflammatory bowel disease also contribute to disordered eating through the associated somatic GI complaints, while pelvic floor dysfunction and Ehlers-Danlos syndrome contribute through both somatic symptoms and functional symptoms. Indeed, functional GI symptoms remain problematic during the course of treatment, and further research is required to better understand the extent to which these symptoms are functional in nature and remit or remain as treatment ensues.