Anorectal complications in long-term Crohn's disease are frequent and evaluation of inflammatory changes in the lower pelvic region is difficult. Abnormalities are fistulas and abscesses which can be demonstrated rapidly and easily by endosonographic measures. Further topographical localization of the abnormalities is possible. Over a period of 2 yr, 55 patients with anorectal complications were examined. Using endosonography, 46 fistulas were found in 36 patients. Forty patients presented inflammatory changes. Abscesses were demonstrated in four cases. Our findings were verified by surgery, fistulography, and correlation with clinical course of illness. Limiting factor of the examination procedure proved to be painful and strictures in male patients, whereas in female patients the alternative of performing the examination via vagina was given. Our results demonstrate that endosonography is an excellent screening method for detecting and evaluating fistulas and abscesses in Crohn patients. Omitting radiation exposure is a further advantage of endosonography.