Bowel Obstruction

Topic Overview

What is a bowel obstruction?

A bowel obstruction is a partial or complete blockage in the intestines that prevents gas, fluids, or solids from moving through the intestines normally. Blockage may occur in the small intestine (small-bowel obstruction) or the large intestine (colonic obstruction or large-bowel obstruction). In severe cases, the bowel's blood supply may be cut off. This is called ischemic bowel or bowel strangulation and requires emergency treatment.

What causes a bowel obstruction?

A bowel obstruction can be caused by tumours, twisting or narrowing of the intestines, or scar tissue (adhesions); these are called mechanical obstructions. Obstructions can also occur because of inflammation or infection or as a side effect of certain medicines. These are called non-mechanical obstructions (or ileus) and are not included in this topic.

In the small intestine, obstructions are most often caused by scar tissue (adhesions). Other causes include hernias, Crohn's disease, and cancer. A blockage can also occur if one part of the intestine folds like a telescope into another part, which is called intussusception.

In the large intestine, obstructions are most often caused by cancer. Other causes are severe constipation from a hard mass of stool and twisting or narrowing of the intestine that may occur because of diverticulitis or inflammatory bowel disease.

What are the symptoms?

A small-bowel obstruction may cause:

• Cramping abdominal pain, which may be severe if the blood supply is cut off (strangulated).
• Vomiting.
• Bloating.

Symptoms of a large-bowel obstruction include:

• Abdominal pain, which may be severe if the blood supply is cut off (strangulated).
• Bloating.

A partial blockage of either intestine may cause occasional diarrhea. A complete obstruction will cause constipation and a noticeable lack of gas (flatus) leaving the body.

How is a bowel obstruction treated?

Treatment for a partial blockage in either the small or large intestine usually takes place in the hospital. Treatment involves monitoring you closely and making you more comfortable while waiting to see whether the blockage goes away on its own.

You usually are not allowed to eat or drink. You will probably receive fluids by IV (intravenously) to keep your blood pressure normal and prevent dehydration. You may have a thin tube called a nasogastric (NG) tube placed in your nose and down into your stomach to remove fluids and gas; this may relieve pain and pressure.

For partial obstructions, non-surgical treatments are usually tried first. These may include using liquids or air (enemas), small mesh tubes (stents), or medicine to open up the blockage.

Surgery is almost always needed for a complete obstruction of the small or large intestine or when the blood supply is cut off (strangulation).

Obstructions can recur if the underlying cause is not treated.

Frequently Asked Questions

Learning about a bowel obstruction:	What is a bowel obstruction? What causes a bowel obstruction? What are the symptoms of a bowel obstruction? What is an incarcerated hernia?
Being diagnosed:	How will my doctor diagnose a bowel obstruction? What will my doctor ask during a medical history? What happens during the physical examination? Are there conditions with similar symptoms? What is a non-mechanical obstruction?
Getting treatment:	How is a bowel obstruction treated? What is the treatment for a bowel obstruction caused by inoperable cancer? What is the treatment for a bowel obstruction caused by twisting of the intestine?
Ongoing concerns:	Will I need to make any lifestyle changes?

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Author:	Carrie Henley Monica Rhodes	Last Updated: July 20, 2007
Medical Review:	Kathleen Romito, MD - Family Medicine Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology
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