Gastrointestinal (GI) symptoms are extremely common in EDS/HSD, and the GI tract is one of the more vulnerable organ systems affected in this disorder. GI disorders may be divided into two categories: functional and structural. GI disorders are usually the result of P&S (autonomic) nervous system dysfunction(s), including GI dysmotility, MCAS, and possibly autoimmune factors. These dysfunctions may lead to irritation and inflammation of the GI structure. Often, by the time the inflammatory symptoms or disorders present, the dysmotility and other inflammatory processes, and therefore the P&S dysfunction(s), have been present for much longer. Structural GI disorders, such as median arcuate ligament syndrome and hiatal hernia, may predispose patients to various GI symptoms in the upper GI tract, whereas rectoceles are structural abnormalities that involve defects in the structure of the lower rectum and may cause worsening constipation. Specific studies of significant populations document the following common structural disorders: hiatal hernia, rectal evacuatory dysfunction, rectal prolapse, anterior rectocele, diverticulosis or diverticulitis, early satiety, bloating and distension, dysphagia, rumination, dyspepsia, reflux-heartburn, frequent or cyclic vomiting, visceroptosis of the bowel, pelvic organ prolapse, short segment intussusception, other obstructive defecation symptoms, which include straining, incomplete evacuation, alternating bowel habits, diarrhea, constipation, abdominal pain, postprandial fullness, and may include the liver. The association of inflammatory bowel disease, celiac disease, Crohn’s disease, and ulcerative colitis has been demonstrated, but not well-studied. These involve inflammation and may start as functional disorders, often due to early P&S dysfunction. Any or all of these symptoms may at times be severe in EDS/HSD patients. More than one GI symptom is commonly present.