Megacolon Health Dictionary

  1. Health Encyclopedia
  2. Megacolon

Megacolon: From 3 Different Sources

A gross distension (enlargement) of the colon, usually accompanied by severe, chronic constipation.

In children, the main causes of megacolon are anal fissures, Hirschsprung’s disease, and psychological factors that may have arisen during toilet-training. In elderly people, causes include the long-term use of strong laxative drugs. People suffering from chronic depression or schizophrenia often have megacolon. Other, rarer causes include hypothyroidism, spinal injury, and drugs such as morphine and codeine.

Megacolon causes constipation and abdominal bloating. Associated loss of appetite may lead to weight loss. Diarrhoea may result if semi-liquid faeces leak around the obstructing hard faeces.

Diagnosis is made by proctoscopy, barium X-ray examination, and tests of bowel muscle function. If Hirschsprung’s disease is suspected, biopsy of the large intestine may be performed. Impacted faeces are often removed using enemas. In severe cases, the faeces must be removed manually.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
A greatly enlarged colon that may be present at birth or develop later. It can occur in all age groups and the condition is typi?ed by severe chronic constipation. Megacolon is caused by obstruction of the colon which may be due to faulty innervation, or to psychological factors. Other causes are HIRSCHSPRUNG’S DISEASE or ULCERATIVE COLITIS. In old people the persistent use of powerful laxative drugs may cause the condition.
Health Source: Medical Dictionary
Author: Health Dictionary
n. pathological dilatation of the colon. It is caused by chronic obstruction of the colon (e.g. due to *Hirschsprung’s disease) or longstanding constipation, or it may occur as a complication of *ulcerative colitis (toxic megacolon).
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Hirschsprung’s Disease

Hirschsprung’s disease, or MEGACOLON, is a rare congenital disorder characterised by great hypertrophy and dilatation of the colon (see INTESTINE). The RECTUM and lower colon have failed to develop a normal nerve network, thus disturbing normal contraction and expansion of these structures. Treatment is surgical removal of the affected sections, with the remaining colon being joined to the anus.... hirschsprung’s disease

Mega-

A prefix meaning very large, as in megacolon, a condition in which the colon is greatly enlarged.

The prefix megalo- has the same meaning.... mega-

Ulcerative Colitis

Chronic inflammation and ulceration of the lining of the colon and rectum, or, especially at the start of the condition, of the rectum alone. The cause of ulcerative colitis is unknown, but the condition is most common in young and middle-aged adults.

The main symptom of ulcerative colitis is bloody diarrhoea; and the faeces may also contain mucus. In severe cases, the diarrhoea and bleeding are extensive, and there may be abdominal pain and tenderness, fever, and general malaise. The incidence of attacks varies considerably. Most commonly, the attacks occur at intervals of a few months. However, in some cases, there may be only a single episode.

Ulcerative colitis may lead to anaemia, caused by blood loss. Other complications include a toxic form of megacolon, which may become life-threatening; rashes; aphthous ulcers; arthritis; conjunctivitis; or uveitis. There is also an increased risk of cancer of the colon developing (see colon, cancer of).

A diagnosis is based on examination of the rectum and lower colon (see sigmoidoscopy) or the entire colon (see colonoscopy), or is made by a barium enema (see barium X-ray examination). During sigmoidoscopy or colonoscopy, a biopsy may be performed. Samples of faeces may be taken for laboratory analysis in order to exclude the possibility of infection by bacteria or parasites. Blood tests may also be needed.

Medical treatments of ulcerative colitis include corticosteroid drugs and sulfasalazine and its derivatives. Colectomy may be required for a severe attack that fails to respond to other treatments, or to avoid colonic cancer in those people who are at high risk.... ulcerative colitis

Hirschsprung’s Disease

a congenital condition in which the rectum and sometimes part of the lower colon have failed to develop a normal nerve network. The affected portion does not expand or conduct the contents of the bowel, which accumulate in and distend the colon. Symptoms, which are usually apparent in the first weeks of life, are vomiting, constipation, abdominal distension, and intestinal obstruction. Diagnosis is by rectal biopsy (to confirm the absence of nerve cells), anorectal *manometry, and imaging. Treatment involves surgical removal of the affected segment and anastomosis of the remaining healthy bowel to the anus. See also megacolon. [H. Hirschsprung (1830–1916), Danish physician]... hirschsprung’s disease

Health encyclopedia icon Health Encyclopedia

Recent Searches