GASTROENTEROLOGY ARTICLE OF THE WEEK
March 25, 2004
Gan SI, Beck PL. A new look at toxic megacolon: An update and review of the incidence, etiology, pathogenesis and management. Am J Gastroenterol 2003;98:2363-2371.
1. Causes of toxic megacolon (TM)
a. the most common infectious cause is salmonella colitis
b. TM does not occur in radiation colitis or Crohn’s disease
c. The most common cause of TM is ulcerative colitis
d. C. difficile colitis is a rare cause of TM
e. In UC, TM develops only in patients with pancolitis
2. Clinical features of TM include
a. transverse colon diameter of 10cm in a patient with no systemic symptoms
b. fever >101.5, tachycardia, leukocytosis and normal abdominal X-rays
c. dehydration, obtundation, leukocytosis temperature of 99 degrees, 7cm
transverse colon in a patient with ulcerative colitis
d. small bowel, gastric and colonic distention in a patient with UC, fever of 102
degrees, altered mental status, blood in rectal exam and no diarrhea
3. Medical management of TM
a. IV steroids predispose to TM and increase risk of perforation
b. broad spectrum antibiotics are recommended
c. TPN should be initiated as soon as the diagnosis is established
d. High dose oral ASA therapy helps in resolution of TM
e. Cyclosporin is not recommended as standard of care for these patients.
f. Trial of medical therapy should be undertaken before total colectomy
True or False
4. Toxic megacolon is segmental or diffuse dilation to >6cm in the presence of acute colitis or signs of systemic toxicicty.
5. An abdominal CT is recommended in patients with suspected TM.
6. A colonoscopy to define the extent of inflammation and decompress the colon in patients with TM is encouraged.
7. Dilated stomach or small bowel in patients with UC may predict progression to TM and is a marker of poor prognosis.
8. A reduction in the frequency of bowel movements in a patient experiencing a flare of ulcerative colitis could be the initial symptoms of TM.
