Gastrointestinal Manifestations and Nutrition Support in Hypermobile Ehlers-Danlos, Postural Orthostatic Tachycardia, and Mast Cell Activation Syndromes.

PURPOSE OF REVIEW: Gastrointestinal symptoms are common and often severe in patients with hypermobile Ehlers-Danlos syndrome/hypermobility spectrum disorders (hEDS/HSD), postural orthostatic tachycardia syndrome (POTS), and mast cell activation syndrome (MCAS). This review provides a structured, practical framework for evaluation of gastrointestinal symptoms and appropriate use of nutrition support in this population, where clinical practice remains variable and escalation to non-oral nutrition support may occur prematurely. RECENT FINDINGS: Emerging data highlight the high prevalence of disorders of gut-brain interaction, avoidant/restrictive food intake disorder, and malnutrition in these overlapping conditions. Evidence suggests that enteral and parenteral nutrition are frequently initiated without adequate trials of conservative and behavioral interventions, and that de-escalation once advanced nutrition support is established remains challenging. A coordinated evaluation integrating validated tools should precede escalation to non-oral nutrition support. Enteral nutrition is preferred when oral strategies fail, and parenteral nutrition should be reserved for intestinal failure. A multidisciplinary, biopsychosocial care model is essential to optimize outcomes and reduce unnecessary harm in this complex population.