Radiation therapy uses X-rays to destroy colorectal cancer cells. It is often combined with surgery or chemotherapy. Radiation therapy may also be used to reduce the cancer's size when it is blocking the colon or rectum or to relieve pain.
Tests to help your doctor see if colorectal cancer has metastasized or recurred include: An abdominal ultrasound to find the cause of pain or swelling in your abdomen. A colonoscopy to see if cancer has returned to your intestine. Blood tests to find out