The gastrointestinal symptoms present in patients with postural tachycardia syndrome: A review of the literature and overview of treatment

Orthostatic intolerance, including postural tachycardia syndrome, is often associated with gastrointestinal symptoms. In the vast majority of the cases, the gastrointestinal symptoms are not secondary to the orthostatic disorder, but rather just a comorbid condition. This concept is critical, since treatment aimed at the orthostatic condition will not improve the gastrointestinal symptoms. Only when the gastrointestinal symptoms develop in the upright position and improve or resolve in the supine position, they may be related to the orthostatic stress. The most common symptoms associated with orthostatic intolerance include nausea, dyspepsia, bloating and constipation. The majority of subjects do not have gastroparesis. The chapter discusses available treatments of these conditions.