Gastrointestinal symptoms in postural tachycardia syndrome: a systematic review.

Gastrointestinal symptoms are among the most common complaints in patients with postural tachycardia syndrome (POTS). In some cases, they dominate the clinical presentation and cause substantial disabilities, including significant weight loss and malnutrition, that require the use of invasive treatment to support caloric intake. Multiple cross-sectional studies have reported a high prevalence of gastrointestinal symptoms in POTS patients with connective tissue diseases, such as Ehlers-Danlos, hypermobile type, and in patients with evidence of autonomic neuropathy. Previous studies that evaluated gastric motility in these patients reported a wide range of abnormalities, particularly delayed gastric emptying. The pathophysiology of gastrointestinal symptoms in POTS is likely multifactorial and probably depends on the co-morbid conditions. In patients with POTS and Ehlers-Danlos syndromes, structural and functional abnormalities in the gastrointestinal connective tissue may play a significant role, whereas in neuropathic POTS, the gastrointestinal tract motility and gut hormonal secretion may be directly impaired due to localized autonomic denervation. In patients with normal gastrointestinal motility but persistent gastrointestinal symptoms, gastrointestinal functional disorders should be considered. We performed a systematic review of the literature related to POTS and gastrointestinal symptoms have proposed possible mechanisms and discussed diagnosis and treatment approaches for delayed gastric emptying, the most common gastrointestinal abnormality reported in patients with POTS.