What Is a Bowel Obstruction?

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A bowel obstruction occurs when a section of the small or large intestine becomes partially or completely blocked. Symptoms include abdominal pain, fevers, constipation, and vomiting. This can be a dangerous condition, potentially increasing the risk of a severe infection or a perforation (hole) in the intestine. Certain medical illnesses such as Crohn's disease increase the risk of bowel obstruction.

Bowel Obstruction Symptoms

A bowel obstruction can begin suddenly or may progress gradually over several weeks or days. Before a complete bowel obstruction develops, you may experience some warning signs caused by a partial bowel obstruction.

Symptoms that often precede a partial or complete bowel obstruction include:

  • Decreased appetite
  • Cramping pain or discomfort
  • Bad breath
  • Changes in bowel movements

The most common effects of a bowel obstruction include:

A complete bowel obstruction prevents stool and gas from passing through. This situation is known as obstipation.

While less common, you can experience overflow diarrhea due to a partial bowel obstruction if a small amount of liquid stool can pass beyond the point of the obstruction.

When to Get Medical Attention

Because some symptoms of impending bowel obstruction are mild, it can be difficult to know when you need to get medical help.

  • If you know you're are at risk of bowel obstruction due to previous bowel obstruction or surgery, call your healthcare provider as soon as you experience symptoms, even if they seem minor.
  • If you aren't at risk, be sure to call your practitioner for persistent constipation or cramping.
  • Seek urgent medical attention if you have severe or persistent abdominal pain, distention, or vomiting.


A bowel obstruction can lead to serious problems. A major infection can develop due to buildup of bacteria in the bowels. In some instances, areas of the bowel may become necrotic (having dead tissue). Necrosis leads to severe infections and/or gangrene.

A perforation in the intestine can occur, resulting in the leakage of bowel contents and/or blood. The symptoms of a bowel perforation include severe pain, abdominal distension, fevers, hypotension (low blood pressure), and loss of consciousness.

A perforation is a medical emergency that requires immediate surgery.


Obstruction can affect any section of the small or large intestine and can occur near the stomach, close to the anus, or anywhere in between.

In a mechanical bowel obstruction, the stool is physically blocked from moving through the intestine. This may be caused by a structural change of the intestines (such as twisting), by something inside the intestine preventing stool from passing through, or by tight constriction outside the intestine.

Having had previous abdominal surgery or a history of bowel obstruction increases the chances that you could develop a sudden bowel obstruction. And there are several other causes and risk factors for bowel obstruction.


A hernia, such as an inguinal hernia or an epigastric hernia, is a weakness in the abdominal lining that keeps the intestines in place. A portion of the intestine can become caught in the hole and the intestine can become squeezed and inflamed, preventing the passage of stool and gas.

Intestinal Mass

Swelling, cancer (such as colon cancer), or infection can grow inside the lumen (opening) of the intestine, making it difficult for the intestinal contents to pass through.

A Large Object

A large, hard stool or an ingested non-food item can become fixed in place, preventing anything from getting past it.


This is a condition that occurs when a section of the bowel slides into itself, shrinking the size of the lumen.


Scar tissue, which can develop after trauma, surgery, or radiation therapy, may cause a tight band-like constriction around the intestine. This type of scarring can develop immediately after an intestinal injury or surgery and it can cause obstruction years afterward.


A volvulus is a twist or kink in the intestine, which can occur due to inflexible scar tissue or gastrointestinal (GI) disease. It may start gradually, with occasional cramping, but then it can worsen quickly, requiring emergency treatment—usually surgery.

Impaired Intestinal Movement

Sometimes myopathy (muscle disease) can impair the movement of the intestines, resulting in a collapse of the lumen, abnormal movements, and obstruction.


Rarely, the bowels may become ischemic (lose blood supply) due to a blood clot. This can happen due to a blood clotting disorder.

Crohn's disease, colitis, lupus, irritable bowel disease, and other inflammatory conditions increase the risk of bowel obstruction through several mechanisms, including constipation, inflammation, and swelling.


The diagnosis of bowel obstruction is made based on your medical history, physical exam, and diagnostic tests. Particularly if you have severe abdominal pain, you need to be evaluated promptly.

After a physical examination, you may have urgent diagnostic imaging tests. Depending on the results, your medical team may also recommend an invasive diagnostic test.

Physical Examination

The bowel normally makes sounds, such as gurgling and clicking, which can be heard with a stethoscope placed on the abdomen. If you have an obstruction, your healthcare provider may hear high-pitched sounds while listening to your abdomen. If the obstruction has been present for some time, there may be a complete absence of any bowel sounds.

Abdominal tenderness (pain in response to touch or pressure) can also give your medical team an idea of how severe your problem is. If your abdomen appears swollen or enlarged, this can also help with the diagnosis.

Diagnostic Tests

A variety of imaging and tests may be used to aid in the diagnosis of a bowel obstruction.

  • X-Ray (abdominal radiograph): An X-ray is normally the first test used to determine if you have an obstruction. It is a non-invasive test that can be performed relatively quickly. Your X-ray may show small, tight areas or enlargement of the intestines and can sometimes identify a mass.
  • Abdominal CT scan: Abdominal CT scans are done similarly to X-rays, and a contrast solution must be taken by mouth, enema (through the anus), or intravenously (IV). A CT scan may show a more detailed image of the abdomen than an X-ray.
  • Colonoscopy: This is an invasive test in which a scope (tube with a camera) is inserted into the rectum to observe the colon from the inside. A colonoscopy can be very helpful to your medical team, but there is a risk involved (especially if you have a bowel obstruction or perforation), so it is not always the right option. It is only used once safety is established with non-invasive imaging tests.
  • Endoscopy: An invasive test in which a scope is placed in your mouth, endoscopy is used to assess the upper parts of your GI system—your esophagus, stomach, and upper small intestine. Like a colonoscopy, there are some risks, and use of this test is guided by preliminary information gathered from your non-invasive imaging tests.


A bowel obstruction is a serious condition that requires urgent treatment within a few days of diagnosis—sometimes, a few hours.

Treatment can include medical management and decompression of the intestine. Surgery may also be used, though some cases of bowel obstruction can be treated without it. However, surgical treatment is often the safest and most definitive option.

If you are prone to this condition, you should work with your healthcare provider to come up with a prevention plan.


In some cases, a stool softener may be considered to help relieve the obstruction. This approach may be considered if you have a partial bowel obstruction.

Because the complications of untreated bowel obstruction are serious, your medical team may consider proceeding to an interventional procedure if medical management does not relieve your obstruction.

Sometimes an antibiotic—usually intravenous (IV, in a vein) is needed to treat or prevent an infection. Antibiotics won't clear the bowel obstruction, but they can help clear an infection.

Intestinal Decompression

In some cases, the intestine can be decompressed with the assistance of a nasogastric (NG) tube. This procedure involves placement of an NG tube through the nose and down into the GI system; your imaging tests would guide your medical team on proper placement.

A rectal tube may be used along with the NG tube to decompress the bowel. A rectal tube is a narrow bore rubber tube that acts to pull out air from the colon. In some situations, a stent, which is an open tube, is placed inside an area of the intestines to keep it open.

This treatment approach would be considered if your obstruction is caused by an object (such as stool) that can be safely moved out of the way.


Surgery may be needed to relieve a bowel obstruction, and it is sometimes necessary to treat complications, such as a bowel leak.

There are several types of surgery for bowel obstruction, including removal of an intestinal mass or tumor, resection (cutting away) of scars and adhesions, and repair of blood vessels. Sometimes, cutting away an area of inflamed or necrotic intestinal tissue is necessary.


It takes a while to recover after treatment of a bowel obstruction. Your medical team will likely check on you frequently to make sure that your pain is improving and that you can pass gas before you will be permitted to eat and drink. In the meantime, you will need IV fluids to maintain nutrition.

Once you can safely start eating again, your diet will advance slowly. This is to allow your intestines a chance to adjust to the food and to quickly catch any signs of recurrent obstruction.

As you are healing, you will have to avoid certain medications, such as opioids (which can cause constipation, increasing the risk of obstruction) and nonsteroidal anti-inflammatory medications (NSAIDS), which can increase the risk of bleeding.


After surgery for treatment of intestinal obstruction, you may need a temporary or permanent colostomy or ileostomy. This is essentially a procedure in which the intestine is actually open to the skin, and waste material is collected in a bag on the outside. Often, the colostomy or ileostomy can be reattached with the remainder of the intestine at a later time.

A Word From Verywell

A bowel obstruction is not a rare event. While treatment is urgently needed and recovery can be a slow process, most many people are able to safely eat a healthy diet thereafter.

However, if you are at risk for recurrent bowel obstruction, take care to avoid foods and habits that predispose you to constipation. Be sure to seek medical attention if you experience symptoms of a bowel obstruction.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.