Patients diagnosed with carcinoma of the rectum are currently treated by a multi-modality approach combining surgery, radiation therapy, and chemotherapy.
 
Following diagnosis by colonoscopy and biopsy, a staging process begins in order to select the best treatment option for any given patient. This process involves a CT scan of the chest, abdomen and pelvis or whole body  examination intended to document or rule out the presence of distant metastasis. In very early tumors or polyps, local excision may be considered in selected patients. In tumors limited to the rectal wall, rectal resection (low anterior resection) with resection of the surrounding lymph nodes (total mesorectal excision, TME) is the treatment of choice without additional radiation or chemotherapy. If the tumor invades through the rectal wall or lymph nodes are involved, a course of combined radiation therapy and chemotherapy is recommended.