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

Abstract

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.

Gastric dilatation in patients with restrictive eating disorders

“…Vettoretto et al (2010) reported that intraluminal gastric contents consisting of even 3 L can distend the stomach to an intraluminal pressure that impedes blood flow and increases risk for gastric necrosis and perforation. Given the high mortality associated with the complications of acute gastric dilatation (Gibson et al, 2021) and the baseline gastric dilatation suggested in this study, future research must better define, and thus differentiate, between the aforementioned acute gastric dilatation and the newly described potential association between enlarged gastric dimensions and malnutrition secondary to an ED; furthermore, future research must seek to understand the impact of the baseline gastric dilatation toward development of the more sinister complications associated with acute gastric dilatation.…”

“…The contribution of the resting gastric dimension toward gastric accommodation and reported GI symptoms in this population requires further investigation. Indeed, reduced gastric accommodation and visceral hypersensitivity are suspected contributors to the symptoms in functional dyspepsia (Di Stefano et al, 2005; Simrén et al, 2018), and functional GI diseases (FGIDs) are highly prevalent in this ED population (Gibson et al, 2021).…”

Diet, Digestion, and the Dietitian: A Survey of Clinicians’ Knowledge, Attitudes and Practices to Advance the Treatment of Gastrointestinal Disturbances in Individuals with Anorexia Nervosa

“…Implementation of routine assessment of GID within the dietetic treatment of AN offers the potential to improve treatment outcomes. Although the efficacy of current dietetic treatment for GID in AN have not been evaluated, malnutrition has a direct impact on the physiology of the GI tract, including altering motility [ 57 ]. Furthermore, engagement in ED behaviours, such as restriction and purging are directly related to GID presence [ 1 ].…”

Assessment and management of disorders of gut–brain interaction in patients with eating disorders

“…With growing awareness of this relationship, research has increasingly focused on identifying DGBIs among patients with EDs, with recent systematic reviews highlighting the most common symptoms [ 19 , 27 ]. More research is certainly needed on shared (e.g., genetic) risk factors for ED and DGBI development.…”