See under STOMACH, DISEASES OF; INTESTINE, DISEASES OF; DIARRHOEA; LIVER, DISEASES OF; PANCREAS, DISORDERS OF; GALL-BLADDER, DISEASES OF; KIDNEYS, DISEASES OF; URINARY BLADDER, DISEASES OF; HERNIA; PERITONITIS; APPENDICITIS; TUMOUR.
Various disease processes that can occur include inflammation, ulceration, infection or tumour. Abdominal disease may be of rapid onset, described as acute, or more long-term when it is termed chronic.
An ‘acute abdomen’ (the term used for the sudden development of abdominal symptoms and signs, usually pain possibly accompanied by diarrhoea and/or vomiting) is most commonly caused by peritonitis – inflammation of the membrane that lines the abdomen. If any structure in the abdomen gets inflamed, peritonitis may result. Causes include injury, inflammation of the Fallopian tubes (SALPINGITIS), and intestinal disorders such as APPENDICITIS, CROHN'S DISEASE, DIVERTICULITIS or a perforated PEPTIC ULCER. Disorders of the GALL-BLADDER or URINARY TRACT may also result in acute abdominal pain.
General symptoms of abdominal disease include:
This is usually ill-defined but can be very unpleasant, and is termed visceral pain. Pain is initially felt near the mid line of the abdomen. Generally, abdominal pain felt high up in the mid line originates from the stomach and duodenum. Pain that is felt around the umbilicus arises from the small intestine, appendix and first part of the large bowel, and low mid-line pain comes from the rest of the large bowel. If the diseased organ secondarily inflames or infects the lining of the abdominal wall – the PERITONEUM – peritonitis occurs and the pain becomes more defined and quite severe, with local tenderness over the site of the diseased organ itself. Hence the pain of appendicitis begins as a vague mid-line pain, and only later moves over to the right iliac fossa, when the inflamed appendix has caused localised peritonitis. PERFORATION of one of the hollow organs in the abdomen – for example, a ruptured appendix or a gastric or duodenal ulcer (see STOMACH, DISEASES OF) eroding the wall of the gut – usually causes peritonitis with resulting severe pain.
The character of the pain is also important. It may be constant, as occurs in inflammatory diseases and infections, or colicky (intermittent) as in intestinal obstruction.
The commonest cause of abdominal swelling in younger women is pregnancy. In disease, swelling may be due to the accumulation of trapped intestinal contents within the bowel, the presence of free fluid ASCITES within the abdomen, or enlargement of one or more of the abdominal organs due to benign causes or tumour.
is the infrequent or incomplete passage of FAECES; sometimes only flatus can be passed, (see main entry for CONSTIPATION). It is often associated with abdominal swelling. In intestinal obstruction, the onset of symptoms is usually rapid with complete constipation and severe, colicky pain. In chronic constipation, the symptoms occur more gradually.
may be due to irritation of the stomach, or to intestinal obstruction when it may be particularly foul and persistent. There are also important non-abdominal causes, such as in response to severe pain, motion sickness or increased pressure within the brain.
is most commonly due to simple and self-limiting infection, such as food poisoning, but may also indicate serious disease, especially if it is persistent or contains blood (see main entry for DIARRHOEA).
is a yellow discoloration of the skin and eyes, and may be due to disease in the liver or bile ducts (see main entry for JAUNDICE).
Abdominal diseases are often difficult to diagnose because of the multiplicity of the organs contained within the abdomen, their inconstant position and the vagueness of some of the symptoms. Correct diagnosis usually requires experience, often supplemented by specialised investigations such as ULTRASOUNDCOMPUTED TOMOGRAPHY (CT) or MRI. For this reason sufferers should obtain medical advice, particularly if the symptoms are severe, persistent, recurrent, or resistant to simple remedies. The situation is a little different in children. About 10% of all those of school age complain from time to time of abdominal pain. Usually a cause cannot be found while sometimes it is a sign of stress or anxiety. Paediatricians usually do few investigations on such children, often no more than checking they do not have a urinary infection and that routine blood tests are normal.