Pictured: José Guillem

Rectal cancer forms inside the large intestine, which is approximately five and a half feet long. The first five feet of the large intestine is called the colon. The rectum makes up the last six inches. This is where stool collects and then passes out of the body through the anus during a bowel movement.

Rectal cancer often develops slowly over several years. It typically starts as a small, abnormal growth on the surface of the rectum called a polyp. Some polyps can eventually turn into cancer. A small percentage of rectal cancers may look different due to a hereditary form of the disease.

Rectal cancer is often contained within the rectum. But when it becomes advanced, the cancer can metastasize (spread) to other organs, most often the liver and lungs.

The rectal cancer experts at Memorial Sloan Kettering use several methods to confirm your diagnosis and determine the stage of your disease. These include physical examination and imaging tests such as CT scans.

Your treatment will depend on the stage of your cancer. You may have surgery, chemotherapy, radiation therapy, or some combination of these. Your treatment will also vary based on how advanced your disease is.

You may also be eligible for a clinical trial exploring a new therapy.