Large Bowel Obstruction

What is a large bowel obstruction?

A large bowel obstruction is a blockage of the large intestine (also called the colon or large bowel). The blockage makes it hard for the contents of the colon to pass through and out of the body.

How does it occur?

Common causes of a blockage are:

• cancer
• inflammation
• twisting of the colon
• a hard lump of stool (fecal impaction).

What are the symptoms?

The symptoms include:

• a change in bowel habits (little or no gas or bowel movements), which may signal the start of an obstruction
• swelling of the abdomen
• abdominal pain
• nausea or vomiting

If the obstruction is only partly blocking the intestine, you may feel temporary relief when liquid stool or gas passes out of the body.

How is it diagnosed?

Your healthcare provider can usually tell if you have a blockage from your symptoms, medical history, and results of a physical exam. However, you may have the following tests to confirm the diagnosis:

• blood tests
• urine test
• X-rays of the chest and abdomen
• colonoscopy, in which the provider inserts a flexible tube through the anus to look at the colon
• X-rays of the bowel after a barium enema
• test of bowel movement for blood
• CT scan, which is a special type of X-ray test.

How is it treated?

Your healthcare provider will give you fluid through a vein in your arm (IV) to keep your body's fluid balance normal. An X-ray of your colon will probably be taken. You will probably have a tube inserted through your nose or throat and down into your stomach to drain fluid and gas trapped behind the blockage. Sometimes a tube inserted into the rectum can temporarily relieve bowel gas and obstruction. You may be given antibiotics and other medicines.

If the blockage is just a hard lump of stool near the anus (fecal impaction), your provider may be able to remove it with an enema or a gloved finger. This usually requires several enemas and may be very uncomfortable.

You may need to have surgery to learn the type and cause of the blockage. If the blockage is caused by cancer, the cancerous part of the colon will be removed. If the obstruction is caused by a twist in the intestine, the surgeon may remove the part of the intestine with the twist, or straighten it out and tack it down so it cannot twist again. If the twisted part has had the blood supply blocked by the twist, it may need to be removed. The surgeon may then rejoin the ends of the intestine. Sometimes a colostomy is necessary when the colon is filled with stool. A colostomy is a surgical procedure in which the surgeon makes an opening for bowel movements in the abdominal wall. In most cases the colostomy is temporary.

How long will the effects last?

Your symptoms will last as long as you have the blockage. If the obstruction is not treated, it can become a life-threatening medical emergency.

What can be done to help prevent a large bowel obstruction?

Exercise daily and eat a diet high in fiber and low in fat and cholesterol. Drinking plenty of water helps your intestines to function normally. If you are not used to high-fiber diets, begin slowly.

If you see blood in your stool or have a change in bowel habits, call your healthcare provider and discuss the changes. Your provider may recommend a colonoscopy to check your colon.

If you are 50 or older, you should have colorectal cancer screening with a test for blood in the stool and a sigmoidoscopy, colonoscopy, or barium enema. You may need to start colorectal cancer screening earlier if a member of your immediate family has had colon polyps or colon cancer, especially if their cancer occurred before they were 50 years old.