Toxic megacolon is a severe inflammatory disorder of the large intestine. This condition usually compromises all layers of the intestinal wall and may spread to the peritoneum, thus giving rise to life-threatening systemic disease.
TM may occur in patients suffering from inflammatory bowel disease or other types of colitis. Thus, patients typically report prior gastrointestinal illness and treatment consistent with risk factors for TM. They should be queried regarding the use of antimotility agents.
TM patients present with constitutive symptoms such as high fever, chills, tachycardia, volume depletion, and reduced levels of consciousness. Patients are acutely ill and often claim abdominal cramps, diarrhea with blood or constipation. A physical examination reveals painful abdominal distention and reduced bowel sounds. Diffuse abdominal rigidity and rebound tenderness indicate peritonitis and may be noted in the case of intestinal perforation. Here, septic shock and multiple organ failure may ensue .
In 1969, Jalan and colleagues defined diagnostic criteria for TM . They are still used today and comprise the following:
Plus either three of the following:
As well as either one of the following:
Diagnostic measures should be undertaken accordingly.
Hematocrit, serum levels of electrolytes, and acid-base status should be assessed repeatedly in order to monitor a patient's response to therapy. At somewhat longer intervals, abdominal radiography should be repeated to evaluate the condition of the colon and the risk of perforation.
Toxic megacolon (TM) is a severe inflammatory disorder affecting parts of or the entire colon. This condition is defined as a non-obstructive dilatation of the colon to diameters exceeding 6 cm and concomitant symptoms of systemic toxicity . TM may complicate cases of ulcerative colitis (up to 10%), Crohn disease (up to 5%), pseudomembranous colitis (up to 3%), and, less frequently, other types of colitis  . It has been suggested that chemotherapeutics, narcotics, anticholinergic and antidiarrheal drugs, discontinuation of steroid administration, and diagnostic measures like colonoscopy may predispose colitis patients for TM, but scientific evidence supporting these hypotheses is scarce.
Mortality rates have been reported to amount to 19% and patients require immediate medical attention to increase their chances of survival. The underlying colitis needs to be treated and disturbances of fluid, electrolyte, and acid-base balance have to be corrected. At the same time, any medication interfering with peristalsis should be withdrawn. Colonic decompression or surgery may become necessary upon disease progression  .