Clinical utility of retrograde terminal ileum intubation in the evaluation of chronic non-bloody diarrhea.

Objective: The aims of this study were to investigate the frequency and factors involved in the terminal ileum intubation of patients with chronic, non-bloody diarrhea and to compare diagnostic yields of colonoscopy and ileocolonoscopy.

Methods: The medical records of 945 patients undergoing colonoscopy for chronic, non-bloody diarrhea were reviewed. Findings of microscopic colitis, Clostridium difficile colitis, celiac disease, inflammatory bowel disease or tropical sprue were considered as definitive causes of diarrhea.

Results: A total of 689 patients met the diagnosis of chronic, non-bloody diarrhea, in which 370 (53.7%) underwent ileocolonoscopy. Specific histological diagnosis could explain the patient's symptoms in 107 (15.5%) patients. The diagnostic yield were 15.0% in the colonoscopy-only group, 16.9% in the ileocolonoscopy without biopsy group, and 15.5% in the ileocolonoscopy with biopsy group. Of the 19 patients with an abnormal terminal ileal biopsy, six (31.6%) had an otherwise normal colonic appearance which would have been diagnosed as normal if the ileum had not been reached and biopsied. In those with Crohn's disease (n = 7), five had ileocolitis and two had colitis only. A multivariate analysis showed that age of the patients and otherwise normal gross endoscopic results to be the only factors associated with a lower likelihood of ileal intubation by endoscopists.

Conclusions: The ileal intubation rate was 53.7% in our patients with chronic, non-bloody diarrhea. Diagnostic yield of ileocolonoscopy with biopsy in US patients with chronic, non-bloody diarrhea appeared to be low, if the colon side was normal on endoscopy. But this may provide supportive evidence in patients diagnosed with ileocolonic Crohn's disease.