Endoscopic ultrasound and endoscopic mucosal resection for rectal cancers and villous adenomas.

EUS is the most accurate tool for local staging of rectal carcinoma. In addition to providing accurate T- and N-stages, EUS allows assessment of the internal and external anal sphincters. Accurate endosonographic staging directs the optimal method of management of rectal carcinoma, type of resection, and candidacy for neoadjuvant therapy. EMR may be applied to large rectal adenomas as an alternative to surgical resection in selected patients. EUS is important in discriminating lesions suitable for EMR.