Endorectal ultrasound.

Endorectal ultrasound is a very useful diagnostic adjunct for benign and malignant anorectal diseases. The only prerequisite in performing this test is that the examiner appreciate the impact that EUS has on the clinical management of patients. For example, the information obtained when scanning rectal cancer dictates whether local excision (i.e., sphincter preservation) or preoperative adjuvant therapy followed by radical resection is chosen. For benign disease, EUS helps direct therapy for patients with fecal incontinence and selects those patients most likely to benefit from reconstructive surgery.