Managing pain due to colorectal cancer

What is colorectal cancer?

Colorectal cancer includes cancer of the large intestine (the long, muscular tube at the lower end of the digestive system) and the rectum (the last six inches of the colon, where waste leaves the body). Colorectal cancers often start as small, noncancerous growths called polyps. If polyps are found during a colonoscopy (a special test for colorectal cancer), they can be taken out before they become cancerous.

What are the signs and symptoms of colorectal cancer?

Colorectal cancers often have no symptoms. When symptoms do appear, they can include:

• Diarrhea or constipation
• A feeling that your bowel does not empty all the way
• Blood in your stool
• Gas pains, cramps or bloating
• Losing weight with no known reason
• Fatigue
• Nausea or vomiting
• Abdominal or rectal pain

How is colorectal cancer treated?

Depending on the stage of the cancer (how far along it is), colorectal cancer is treated with surgery, chemotherapy, radiation, or a mix of all three. Each person’s treatment can be different, based on the size of the tumor and how far it has spread into the colon or rectum. It’s also important to learn if the cancer has spread to the lymph nodes and other organs, like the liver.

Colon surgery

During a partial colectomy, a surgeon cuts out the cancerous part of the colon, along with some of the tissue that’s around it. Once the problem area is gone, the pieces of colon are stitched back together.

A total colectomy removes the whole colon, instead of just a section.

colostomy is an operation that may have to be done if a tumor is so large that it blocks the colon. During this surgery, the end of the large intestine is brought to an opening in the abdomen (called a stoma), so that waste drains from the bowel into a special bag outside the body. This may be temporary, and closed later, or permanent.

  • Laparoscopic surgery is a way to do colon surgery by using only a small incision in the person’s abdomen, and telescope-like devices.

Rectal surgery

The rectum is the last few inches of the colon, where solid waste is held until it goes out of the body through the anus. If a tumor in the rectum is at an advanced stage, surgery can be used to remove all or part of it; sometimes radiation therapy is given before or after this surgery. If cancer is at the lower end of the rectum near the anus, the operation usually will include a colostomy.


Chemotherapy uses strong medicines to kill cancer cells that have spread past the colon to other parts of the body. Chemotherapy may also be used after surgery, even when no signs of cancer are left to keep the rectal cancer from coming back.

Radiation therapy

Radiation treatment helps to shrink early-stage tumors in the rectum before surgery. After surgery, radiation may be used as well.

Radiation therapy isn’t used very often to treat early-stage colon cancer, but it can help to treat advanced rectal cancer.


Another way to treat a cancer that has spread to the liver is to cut off most of the blood flow to the liver’s cancer cells, but not to healthy liver cells. This type of treatment is called embolization.

Colorectal Cancer Pain

Managing pain from colorectal cancer

Colorectal cancer doesn’t cause pain for every patient, but pain could happen at any time from diagnosis and even after treatments are done. Pain from colorectal cancer can be caused by pressure on tissues or organs, or by irritation or pressure on nerves.

If a tumor in the colon is large enough, it could block the intestine, causing pain in the abdomen. If this problem happens, it’s usually necessary to have surgery right away; medications don’t work well to treat this type of pain. Sometimes a colostomy is needed to take care of the blockage.

A rectal tumor could cause such bad pain in the pelvic area that pain medication needs to be injected right into the place where the nerves are located. Destroying the tumor with radiation can also help to take care of the pain.

Colorectal cancer may spread (metastasize) to other parts of the body (like the liver, or bones) and cause pain. Depending on the tumor’s size and location, it may be possible to treat this pain with non-prescription and prescription medication, even before the tumor is treated with chemotherapy.

Managing pain from colorectal cancer treatment

Pain can happen at different times during your cancer treatment. If it happens after surgery, pain medication can be given by mouth or by IV (intravenously). Sometimes pain medication can be placed into the space around the spinal cord; this is called an epidural. It’s also possible for patients to give pain medication to themselves through a special system called patient-controlled analgesia (PCA).

Rectal cancer is sometimes treated with high doses of radiation, which can cause skin around the anus and rectum to break down. This painful problem is often treated with creams and pain medications.

When you’re in pain

Your comfort is an important part of cancer care. With so many medications and treatments on hand to take care of cancer pain, no cancer patient should have to live with untreated pain. Don’t hesitate to tell your doctor or nurse if you’re hurting. While the treatment may not work 100%, it can still make a difference.


American Cancer Society (2008). Overview: colon and rectum cancer. Retrieved 7/1/08 from

National Cancer Institute (2008). Pain Control. Retrieved 7/1/08 from

National Cancer Institute (2006). What you need to know about cancer of the colon and rectum. Retrieved 7/1/08 from