Endosonography of the anal canal and rectum.

Endosonography has evolved into an effective tool for the accurate preoperative assessment of anorectal pathology, from idiopathic anal pain to malignancy. The published data suggest that endosonography is currently the best method for assessing the structural integrity of the anal sphincter and for staging rectal cancer. The development of new treatment modalities for rectal cancer, including local excision, preoperative radiotherapy, and total mesorectal excision, has increased the importance of accurate preoperative staging to allow the optimum treatment planning. However, there is little information about the impact of endosonographic findings on clinical decision making. Education, training, and quality control in the use of endosonography also require further work. This article aims to evaluate the usefulness and limitations of this technique in clinical practice.