ABSTRACT
In the armamentarium of a colorectal surgeon, a good history and physical examination are the first steps toward treatment. A popular tool to augment the physical examination is endorectal ultrasound. The problems that can be evaluated by Anorectal ultrasound (AUS) range from benign conditions such as abscesses and anal fistulae to rectal tumors, both benign and malignant, extent of spread of rectal cancers, node positivity in rectal tumors, and presacral tumors. Most AUS machines in use utilize a two-dimensional view. A tumor appears dark on the AUS, as do any accompanying infiltrated nodes, which have the same echogenicity. It is important during an examination to start identifying the layers of the rectum at the point where they are normal and then trace the layers toward the tumor. AUS is inexpensive and conveniently performed in the office setting. AUS is a valuable imaging modality for several anorectal conditions and is available conveniently in the office.
