Prospective Comparison of Small Bowel Meal with Pneumocolon versus Ileo-Colonoscopy for the Diagnosis of Ileal Crohn's Disease

BACKGROUND AND AIMS: Both endoscopy and barium radiography are used routinely to diagnose terminal ileal (TI) Crohn's disease (CD). A prospective study was undertaken to compare ileoscopy with biopsy to small bowel meal with pneumocolon (SBMP) in patients with suspected TI CD. METHODS: A cohort of outpatients investigated for diarrhea with features of TI disease underwent SBMP followed by colonoscopy with ileal intubation and biopsy within 21 days. All results were reported in a standardized, sequential format to assign SBMP TI diagnoses by the duty radiologist and by dual reading with consensus, ileoscopy by the attending endoscopist, and ileoscopy with biopsy by a blinded panel of endoscopists and pathologists. Reference standard TI diagnoses were determined by a consensus panel with full access to medical records. RESULTS: Among 120 subjects, the reference standard TI diagnosis was normal in 47 (39.1%), lymphoid nodular hyperplasia (LNH) in 24 (20.0%), CD in 48 (40.0%), and NSAID enteropathy in 1 (0.9%). Colonoscopy provided TI images and/or biopsies in 97 cases (80.8%), while SBMP provided TI images in 119 (99.1%). When ileoscopy with biopsy succeeded, its accuracy was similar to SBMP with dual reading (89.7%vs 89.9%, p = NS) but superior to SBMP if interpreted only by the duty radiologist (80.0%, p < 0.05). Biopsy improved the accuracy of ileoscopy, while dual reading improved that of SBMP. Both ileoscopy with biopsy and SBMP with dual reading are highly accurate for diagnosing TI CD. Choice of initial test should reflect local expertise and availability, and the likelihood of associated disease in the proximal small bowel or colon.