Clinical significance of colonoscopic findings associated with colonic thickening on computed tomography: is colonoscopy warranted when thickening is detected?

GOAL: To determine the utility of colonoscopy in the management of patients with abdominal pain found to have colonic thickening on computed tomography (CT).

BACKGROUND: CT is often used in the investigation of abdominal pain. Clinical guidelines regarding colonoscopy when colonic wall thickening is reported at CT are lacking.

STUDY: From July 2000 to April 2004, the abdominal CT reports of all patients at a major teaching hospital who were investigated for abdominal pain were reviewed. Cases were selected if any colonic wall thickening was reported. Patients were excluded if they had a previously diagnosed gastrointestinal condition, or if they had not undergone colonoscopy within 30 days of the abnormal CT. Clinical, endoscopic, and pathologic data were extracted from the medical records of all eligible patients.

RESULTS: One hundred seven cases were identified. Of these, 8 (7.4%) had colorectal adenocarcinoma. In 10 patients (9.3%), a new diagnosis of inflammatory bowel disease (IBD) was made. Sixteen (15.0%) had findings consistent with infectious colitis, 39 (36.4%) ischemic colitis, and 6 patients (5.6%) had miscellaneous findings possibly responsible for the colonic thickening (diverticulitis, appendicitis, proctitis, and melanosis coli). In 28 patients (26.1%), no abnormality was found that could explain the CT finding. Of those diagnosed with colorectal carcinoma or IBD, only 4 of the 18 patients (28%) presented with evidence of gastrointestinal bleeding or anemia.

CONCLUSIONS: On the basis of the rate of new diagnoses of colorectal carcinoma and IBD, we recommend colonoscopy be performed after clinical evaluation in patients with abdominal pain and colonic thickening on CT.