Rectal endosonography in inflammatory bowel disease: differential diagnosis and prediction of remission

There are few and conflicting data on EUS features of the rectal wall in Crohn's disease (CD) and ulcerative colitis (UC). The aim of our study was to determine whether rectal EUS could first differentiate between CD and UC, and secondly predict remission in CD.

During a 14 month period we prospectively and blindly studied several parameters on rectal EUS (total wall thickness, mucosal appearance, submucosal thickness, number of enlarged vessels in the submucosa and number of pathological lymph nodes around the rectum and sigmoid colon) in 20 normal subjects, 26 patients with UC, 39 patients with CD, and four with infectious colitis. Comparisons were made between normal controls, patients with acute UC and those with acute CD, as well as between acute flare-ups and quiescent forms of CD and UC in the same patients.

Normal subjects showed some features which were significantly different from those in CD or UC patients. A greater number of pathological lymph nodes was characteristic for acute UC, whereas the number of enlarged vessels was increased in acute CD. Quiescent CD showed a lower amount of wall thickening than acute CD. No significant alterations of the five parameters were found in quiescent UC compared to acute UC.

This study suggests that EUS could be helpful in differentiating acute UC from CD, and to predict remission in CD.