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.