Bowel Obstruction or Intestinal Blockage

Approved by the Cancer.Net Editorial Board, 12/2020

A bowel obstruction is when a blockage stops food and liquids from moving through your digestive tract. It can also be called an intestinal obstruction, blocked intestine, or a gastrointestinal (GI) obstruction.

There are many possible causes of a bowel obstruction. It is more common in people with certain kinds of cancer and in people with advanced cancer.

A complete obstruction is a medical emergency and may require surgery. A partial obstruction is also a serious problem and needs to be treated right away. It is important to talk with your health care team if you experience any of the symptoms of a bowel obstruction.

Treatment for side effects is an important part of cancer care. This type of treatment is called palliative care or supportive care. Talk with your health care team about any symptoms you have, including new symptoms or changes. This helps them find side effects like a bowel obstruction as early as possible.

What is the gastrointestinal tract?

Your digestive tract or GI tract is made up of the esophagus, stomach, small intestine, and large intestine. It is part of your digestive system.

The small intestine digests nutrients from food and liquids and absorbs them into blood vessels. These nutrients include proteins, fats, and carbohydrates. Remaining food that cannot be digested moves from the small intestine to the large intestine. The colon absorbs water from the waste and stores waste until the next bowel movement, which removes the waste as stool (feces) from the body.

This illustration shows the 5 sections of the colon and rectum. The ascending colon is the beginning the large intestine into which the small intestine empties; it begins on the lower right side of the abdomen and then leads up to the transverse colon. The transverse colon crosses the top of the abdomen from right to left, leading to the descending colon, which takes waste down the left side. Finally, the sigmoid colon at the bottom takes waste a few more inches, down to the rectum. A cross-section of the rectum and sigmoid colon shows where waste leaves the body, through the anus. Copyright 2004 American Society of Clinical Oncology. Robert Morreale/Visual Explanations, LLC.

What are the signs of a bowel obstruction?

A bowel obstruction can happen in the small intestine (small bowel obstruction) or the large intestine (large bowel obstruction). During a bowel obstruction, some or all of the food and liquids that move through the digestive tract are unable to move past the blockage. Intestinal obstructions can be caused by something inside the GI tract blocking the intestine or by something outside the GI tract pressing on the intestine and causing it to collapse.

A bowel obstruction causes physical symptoms, including:

  • Nausea and vomiting

  • Severe pain in your abdomen (belly)

  • Cramping pain from peristalsis, the contractions that move food through your GI tract

  • Visible waves of movement across the belly from peristalsis contractions

  • Bloating

  • Feeling food get stuck as it moves through the GI tract

  • Not being able to pass stool (constipation) or gas

What causes a bowel obstruction?

The common causes of a GI obstruction when you have cancer are:

  • Stool that is hard and difficult to pass

  • Twisting of the intestines

  • Scar tissue in the intestines

  • Inflammation of the intestines after radiation therapy

  • A tumor or tumors inside the GI tract

  • A tumor or tumors pressing on the outside of the GI tract

What types of cancer can cause a bowel obstruction?

GI obstructions can happen with many types of cancer. They are more common in people with:

How is a bowel obstruction diagnosed?

In order to diagnose a bowel obstruction, your doctor will do a physical exam. During this exam, they will feel your abdomen and use a stethoscope to listen to your belly.

A bowel obstruction can often be confirmed with an X-ray. But not all bowel obstructions will show on an X-ray, so you may need to have a CT scan or a barium enema.

How is a bowel obstruction treated?

Most people who have a bowel obstruction require hospitalization. The best treatment for a bowel obstruction depends on what caused it. Some ways to treat or manage a bowel obstruction are:

  • Getting fluids through an intravenous (IV) tube that goes into a vein in your arm. Not eating or drinking for a few days can help reset and reverse twisted bowels. If the blockage is not improving after a few days, you may also need IV nutrition.

  • Enemas or medication to loosen and/or soften a hard stool causing a blockage.

  • Using a tube to remove air and fluid in your stomach to prevent more pain. Called a nasogastric tube, this tube goes in through your nose and down into your stomach.

  • Taking medicine your doctor recommends to relieve nausea and vomiting, diarrhea, swelling, or pain.

If these options do not work, your doctor may suggest:

  • Surgery to fix the blockage and clear a path for food to go through your GI tract.

  • An expendable tube called a stent. This holds open the blocked area of the GI tract temporarily.

  • An ileostomy. This surgery can help your large intestine and rectum heal after a blockage. During an ileostomy, a temporary or permanent opening (stoma) is placed from the lowest part of the small intestine to the outside of your abdomen. Waste is collected in a pouch worn on the outside of your body and does not need to pass through the large intestine or the colon.

  • A colostomy. This surgery can help parts of your large intestine and rectum heal after a blockage. During a colostomy, a temporary or permanent opening (stoma) is placed from the large intestine to the outside of your abdomen. Waste is collected in a pouch worn on the outside of your body and does not pass through the rectum.

Questions to ask the health care team

  • Is a bowel obstruction a common side effect of the kind of cancer I have?

  • If I'm at risk for a blockage, what signs or symptoms should I watch out for?

  • Who should I contact if I have any signs or symptoms of a bowel obstruction? How soon?

  • What is causing my bowel obstruction? How can it be treated?

  • Is there medication I can take to relieve the symptoms of a bowel obstruction?

  • If needed, what kind of surgery would you recommend to treat my bowel obstruction? What will my recovery be like?

  • Should I keep track of my bowel movements or cancer side effects during treatment? If so, what is a good way to track them?

Related Resources


How to Live with an Ostomy Bag

How to Thrive While Living with an Ostomy Bag

More Information

National Cancer Institute: Gastrointestinal Complications