Small Bowel Obstruction

Small Bowel Obstruction

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Small Bowel Obstruction

A small bowel obstruction occurs when there is partial or total blockage in the small intestine (bowel). As a result, digestive contents cannot move through the bowel properly and out of the body. Treatment is needed right away to remove the blockage. This can relieve painful symptoms. It can also prevent serious complications, such as tissue death or rupture of the small bowel. Without treatment, a small bowel obstruction can be fatal.

Causes of small bowel obstruction

Outline of human figure showing digestive system and pointing out small intestine, large intestine, and rectum. Detail of obstruction trapping part of small intestine. Trapped intestine is damaged.

A small bowel obstruction can be caused by:

  • Scar tissue (adhesions). These may form after surgery or an infection.

  • Hernia (weakness or tear in the wall of the abdomen). This can cause a portion of the small bowel to push out and appear as a visible bulge under the skin.

  • Certain medical conditions. These include intussusception (occurs when a portion of the bowel slides inside another portion) and irritable bowel disease (IBD) such as Crohn’s disease and ulcerative colitis (illness that causes inflammation in the intestine).

  • Abnormal tissue growths (tumors). These can form on the inside or outside of the small bowel, and are usually due to cancer.

Symptoms of small bowel obstruction

Common symptoms include:

  • Abdominal cramping and pain

  • Abdominal swelling and bloating

  • Nausea and vomiting

  • Inability to pass gas

  • Inability to pass stool (constipation)

  • Diarrhea

Diagnosing small bowel obstruction

Your doctor will ask about your symptoms and health history. You’ll also have a physical exam. In addition, tests may be done to confirm the problem. These can include:

  • Imaging tests. These provide pictures of the small bowel. Common tests include X-rays and a computed tomography (CT) scan.

  • Blood tests. These check for infection and other problems,, such as dehydration.

  • Upper gastrointestinal (GI) series with a small bowel follow-through. This test is done to take X-rays of the upper digestive tract from the mouth through the small bowel. A contrast fluid is used. The contrast fluid coats the inside of the upper digestive tract so it will show up clearly on X-rays.

Treating small bowel obstruction

Treatment takes place in a hospital. As part of your care, the following may be done:

  • No food or drink is given by mouth. This allows your bowels to rest.

  • An intravenous (IV) line is placed in a vein in your arm or hand. The IV line is used to give fluids. It may also be used to give medications. These may be needed to relieve pain, nausea, and other symptoms. They may also be needed to treat or prevent infections.

  • A soft, thin, flexible tube (nasogastric tube) is inserted through your nose and into your stomach. The tube is used to remove extra gas and fluid in your stomach and bowels. This helps to relieve symptoms such as pain and swelling.

  • In severe cases, such as when the small bowel is almost or totally blocked, or there is a bowel perforation, surgery is done. During surgery, the blockage is removed. Portions of the bowel may also be removed if there is tissue death. Other repair may be done as well, depending on the cause of the blockage. Your doctor will give you more information about surgery, if needed.

  • You’ll be observed in the hospital until your symptoms improve. Your doctor will tell you when you can return home.

Long-term concerns 

After treatment, most people recover with no lasting effects. If a long portion of the bowel is removed, there is a greater chance for lifelong digestive problems, such as irregular bowel movements. Work with your doctor to learn the best ways to manage any symptoms you may have and to protect your health.


When to call the doctor

Call your doctor right away if you have any of the following:

  • Abdominal swelling or cramping that won’t go away

  • Inability to pass stool or gas

  • Nausea or vomiting (especially if the vomit looks or smells like stool)

  • Severe pain (Call 911)