Colonoscopy, Upper endoscopy, Esophageal manometry, Gastric emptying study, Gastrointestinal transit study, Breath test...ing, Anorectal manometry, Impedance pH testing, pH testing, Bravo capsule pH test, Constipation, Irritable bowel syndrome, Indigestion, Dysphagia, Achalasia, Gastroesophageal reflux disease, Functional dyspepsia, Gastroparesis, Pelvic floor dysfunction, Small intestinal bacterial overgrowth, Intestinal pseudo-obstruction, Visceral pain