Staging colorectal carcinoma.

Colorectal cancers are the second most common tumor in the United States and the most common gastrointestinal cancer. Preoperative staging with computed tomography, magnetic resonance imaging, and endorectal ultrasonography has some limitations. Their routine use has not been established. Endorectal ultrasonography may prove valuable in patients with rectal tumors. Computed tomography is the recommended procedure for follow-up imaging in colorectal cancer patients.