What is a small bowel obstruction?

The small bowel is the small intestine. A small bowel obstruction is a blockage of the small intestine.

The small bowel begins at the end of the stomach and ends where the colon (large intestine) starts. In most adults, the small bowel is about 21 feet long.

The bowels can become trapped outside the abdominal cavity. When blood flow to the blocked part of the bowel is cut off and the bowel wall begins to die, it is said to be strangulated. This can be life threatening, but occurs in only one-fourth to one-third of cases of small bowel obstruction.

How does it occur?

The major cause of small bowel obstruction are adhesions. Adhesions are bands of scar tissue that form after surgery. The adhesions grow across sections of the bowel, trapping portions. Other causes include:

• Hernia, a weakness in the wall of the abdomen through which the intestines protrude
• Inflammatory bowel disease
• The intestine folding into itself, cutting off normal flow of partly digested food, and eventually cutting off blood flow to the tissues
• A twisted or knotted bowel
• A narrowing of bowel that you were born with
• A lack of oxygen flow to the bowel, causing part of the bowel to die
• Cancer.

What are the symptoms?

The symptoms of a blocked small bowel include:

• A tender and enlarged abdomen
• Cramp like pain in the abdomen
• Vomiting
• Slight fever
• Failure to pass gas or stools
• Lack of enough water in the body (dehydration), which can cause flushed, dry skin; coated tongue; weakness; and confusion.

How is it diagnosed?

Your doctor will review your symptoms, take your medical history, and examine you. He or she will ask about previous surgeries, bowel blockages, and hernias. The doctor may order the following tests:

• Blood tests
• X-rays of the chest and abdomen
• X-rays of the bowel after a barium enema
• Endoscopy or colonoscopy, which is examination of the colon through a long, flexible tube.

How is it treated?

If your small bowel is partly blocked, the treatment may include decreasing the pressure of bowel gas by passing a tube through your nose to your stomach. Your doctor may prescribe antibiotics. You may need IV fluids to replace lost fluids and to prevent further dehydration.

You may need surgery if your small bowel is completely blocked. The decision to operate is based on the following:

• Too many white blood cells, indicating infection
• Strangulation, caused by not enough blood reaching the affected area of the bowel
• Worsening symptoms
• Tenderness of your abdomen
• Blood in your stool
• Air under your diaphragm (the sheet of muscle that separates your chest from your abdomen), which means there is a hole in the wall of your abdomen
• An infection in the lining of your abdomen.

If you need an operation, the surgeon will make a cut through the wall of your abdomen and relieve the blockage. The surgeon may remove a portion of bowel. Your doctor may prescribe antibiotics for infection.

How long will the effects last?

How long the effects last depends on what caused the blockage and whether the bowel has been strangulated. It is important to get up and walk as soon after surgery as is reasonable. Walking helps get the bowel to start moving again.

How can I help prevent small bowel obstruction?

Some people believe a diet high in fiber and low in fat and cholesterol reduces the chances of getting a blockage of the small bowel. Increase your fiber gradually because sudden increases have actually caused blockages. Avoiding constipation is also important. You should drink plenty of fluid. If you have a hernia that may cause a problem, get it repaired.