ABSTRACT
Anal endosonography (AES) for evaluation of perianal disorders was introduced by P. J. Law and co-workers in an attempt to identify the fistula tract with regard to the anal sphincters. The use of the AES for preoperative assessment of the fistula in ano and abscesses seems obvious. Special preoperative identification of the trajectory of the fistula tract in relation to the sphincters is important. S. Choen et al. in a prospective trial, compared the accuracy of digital examination under anesthesia and AES in the evaluation of anal fistulas. The AES can be used for pre-as well as postoperative assessment of the perianal area and the sphincters in patients who will be operated because of polyposis coli or ulcerative colitis. The clinical and AES evaluation of patients after operation is interesting for the understanding of the consequences of perianal surgical procedures on the sphincter mechanism.
