There are many causes of abdominal pain, ranging from life-threatening emergencies to chronic functional disorders and dysfunctions of certain organs and systems. Acute abdominal pain requires rapid identification of the possible cause and early initiation of appropriate treatment. After the abdominal pain has subsided, further detailed and comprehensive investigations can be performed to clarify the diagnosis. Clinical features Nature and location of abdominal pain: Visceral pain (due to changes in cavernous organ tone) is poorly localized and usually presents in the midline. Intra-intestinal pain is mostly colicky and is usually localized in the umbilicus and periumbilical region when the site is close to the ileocecal valve. Pain of colonic origin is mostly in the lower or left lower abdomen. Pain from biliary or urinary tract obstruction is more severe and can cause the patient to toss and turn. Somatic pain (due to peritoneal inflammation) is more intense and better localized (e.g., acute appendicitis, peritoneal distension of a substantial organ such as the liver, kidney, or spleen), and movement may aggravate the pain and cause the patient to remain immobile. The radiation of the pain is also diagnostically helpful: radiation to the right shoulder suggests a hepatobiliary origin, the left shoulder suggests the spleen, the back suggests the pancreas, the hypochondrium suggests the proximal urinary tract, and the groin suggests the genital or distal urinary tract. Aggravating or remitting factors: Ask the patient about the relationship of exacerbation or remission to diet (e.g., upper gastrointestinal, biliary, and pancreatic diseases, localized ischemic bowel disease), to defecation (colorectal disease), to urination (genitourinary disease or colorectal disease), to respiration (pleuropulmonary disease, hepatobiliary disease), to posture (pancreatic disease, gastroesophageal reflux, muscle and bone disease), to menstrual cycle (tubo-ovarian disease, endometrial disease including endometriosis), with exertion (coronary or intestinal local ischemia, musculoskeletal disease), with medications and special dietary history (power dysfunction, food intolerance, gastroesophageal reflux, porphyria, hyperaldosteronism, ketoacidosis, toxins), and with stress (power dysfunction, no ulcerative dyspepsia, intestinal stress syndrome) Concomitant symptoms: with fever, chills (infection, inflammatory disease), with weight loss (tumor, inflammatory disease, malabsorption, local ischemia), with nausea, vomiting (obstruction, infection, inflammatory disease, metabolic disease), with dysphagia, painful swallowing (esophageal disease), with early satiety (gastric disease), with vomiting blood (esophageal, gastric, duodenal disease) constipation (colorectal, perianal, genitourinary diseases), jaundice (hepatobiliary, hematologic diseases), diarrhea (inflammatory diseases, infections, malabsorption, secretory tumors, local ischemia, genitourinary diseases), dyspareunia, hematuria, vaginal or penile radiating pain (genitourinary diseases), blood in the stool (colorectal diseases, rarely urinary diseases)