Toxic Colitis

Toxic colitis (TC) refers to an acute severe colitis which threatens life of the child. When associated with megacolon it is called toxic megacolon (TM). Toxic megacolon is an acute dilatation of the colon associated with symptoms of toxemia such as abdominal distension, constipation, reduced bowel sounds and fever, tachycardia or hypotension. The colonic dilatation can be total or segmental depending on the incipient disease that cause it. Patients can develop toxicity without megacolon.  The hallmark of toxic megacolon (or colitis) is a nonobstructive transverse colonic dilatation larger than 6 cm associated with signs of systemic toxicity such as fever above 101.5 F, tachycardia and leukocytosis or anemia. The child might also present bloody stools, dehydration, altered metal status, electrolytes abnormalities and hypotension. Toxic colitis (or megacolon) is mostly a complication of ulcerative colitis but can be seen in other inflammatory disease such as Crohn, ischemic colitis, infectious colitis associated with Clostridium difficile, after radiation therapy or with Hirschsprung's disease.  The most dreaded complication of toxic colitis with megacolon is perforation of the colon. Since many children with ulcerative colitis are in steroid therapy, the classic signs of peritonitis are absent when free perforation occurs due to a blunt systemic inflammatory response from the steroids. The microscopic hallmark of TC or TM is transmural inflammation extending beyond the mucosa into the smooth-muscle layers and serosa. The extent of dilatation correlates with the depth of inflammation and ulceration. Medications such as anticholinergics, antidepressants, loperamide and opioids negatively impact bowel motility and could be implicated in cases of TM. The prognosis with medical management of TM is poor though with tumor necrosis factors alpha inhibitors more cases can be managed medically. When TC or TM is established surgery will be needed. Total colectomy with ileostomy is the procedure of choice in the very acute situation. Later proctectomy with j-pouch ileal reconstruction can be performed.

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