Obstruction, Perforation of gastrointestinal tract, Mesenteric ischemia, IBD: ulcerative colitis and Crohn disease, Viral gastroenteritis, Spontaneous bacterial peritonitis (SBP), Peritonitis in peritoneal dialysis patients, Malignancy (colorectal, gastric, pancreatic cancer), Celiac disease, Ketoacidosis, Adrenal insufficiency, Foodborne disease (toxins, bacterial colitis), Constipation, Diverticulosis, Lactose intolerance.