What is a bowel obstruction?

Bowel obstruction (also called intestinal obstruction) is when something blocks the normal movement of food and liquids through your bowel (intestines). It can happen for a variety of reasons.

There are different types of bowel obstruction. A blockage in your digestive system can be:

• in the small intestine or the large intestine
• partial (meaning your bowel is partly blocked and some faeces (poo) can still get through) or complete (meaning it is fully blocked and not even gas can get through)
• simple (just a blockage) or complicated (meaning the blockage has cut off your bowel's blood supply and caused damage to your bowel)

What are the symptoms of bowel obstruction?

The symptoms of a bowel obstruction depend on where the blockage is and the cause.

Small bowel obstruction

Symptoms of a small bowel obstruction come on quickly. You may notice:

• cramping or abdominal pain, especially in your upper abdomen and around your belly button
• inability to pass gas or bowel motions
• vomiting
• diarrhoea — if your bowel is partially blocked

If your pain is severe and constant, this may mean the blockage is affecting the blood supply to your bowel.

Large bowel obstruction

Symptoms of a large bowel obstruction come on gradually and are usually less severe. You may notice:

• constipation that gets worse until you can't pass any bowel motions or gas
• bloating
• cramps in your lower abdomen
• vomiting — this is uncommon and may start after the other symptoms

However, in some cases a large bowel obstruction can cause sudden constant pain. It depends on what is causing the obstruction.

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What causes bowel obstruction?

There are many reasons for bowel obstruction. Depending on your age and medical history, you might be more susceptible to certain types of bowel obstruction.

In adults, the most common causes of bowel obstruction are:

• adhesions — these are scar-like bands of tissue that can form between organs that shouldn't be connected, usually after abdominal or pelvic surgery
• tumours
• hernias

Other causes include:

• inflammatory bowel disease, such as Crohn's disease
• diverticulitis
• volvulus — when part of the bowel twists
• intussusception — when part of the bowel folds in on itself (more common in children)
• a foreign body, such as a swallowed object or gallstones
• severe constipation

What is a pseudo-obstruction?

This is different type of bowel obstruction, also known as a functional bowel obstruction. This occurs when your bowel muscles are not contracting properly and can't push faeces along, even though there is no physical blockage.

It causes the same symptoms as a mechanical (physical) bowel obstruction.

Possible causes include:

• abdominal surgery
• injuries
• a muscle or nerve disorder
• abdominal infection
• some medicines, such as opioids
• low potassium

How will my bowel obstruction be diagnosed?

To diagnose bowel obstruction, your doctor will likely:

• ask you questions about your health and symptoms
• examine your abdomen
• refer you for blood tests
• refer you for x-rays or a CT scan of your abdomen

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What treatment will I need?

Treatment for bowel obstruction depends on the cause. You will usually need to go to hospital for treatment and monitoring.

While in hospital, you might have the following treatment:

• Your urine output may be monitored.
• You may get fluids through an intravenous (IV) drip.
• You may receive pain relief and anti-nausea medicines.
• A nasogastric tube may be inserted through your nose and down into your stomach (but usually only if you have severe bloating or vomiting).
• Other procedures, such as colonoscopy or sigmoidoscopy, may be done.
• You may need to have surgery.

Some people need to have surgery immediately. Some people are treated with IV fluids and medicines for 2 or 3 days before having surgery if they are not getting better. However, some people don't need surgery at all.

If your obstruction is caused by bowel cancer, you might need surgery to remove the affected part of your bowel.

How can I prevent bowel obstruction?

There are some types of bowel obstruction you can't prevent, but there are ways to help lower your chance of your bowel becoming blocked.

Diet

If your bowels are normal, fibre is good for you. However, if you know that parts of your bowel are narrowed, you should follow a diet low in insoluble fibre. Insoluble fibre is the hard and rough part of plants that we eat, such as fruit and vegetable skin, whole grains and some nuts and seeds. This type of fibre can get stuck in narrow parts of the bowel.

You can avoid insoluble fibre by:

• peeling, cooking or finely cutting up fruit and vegetables and removing their seeds
• eating white bread, pasta and rice rather than wholegrain
• avoiding nuts and seeds

This type of diet can increase your risk of constipation. To prevent this, make sure to drink lots of water and get some exercise. Talk to your doctor about whether you might need a laxative medicine.

Also, it is important to cook your food well, avoid tough and stringy food, and chew well before swallowing.

It may be helpful to discuss your diet and nutrition with a dietitian.

Preventing causes

There are also ways to prevent some of the causes of bowel obstruction.

It's important to avoid smoking, to lower your risk of developing bowel cancer or a hernia.

You can also lower your risk of bowel cancer by:

• including dairy products, whole grains and fibre in your diet and limiting red meat and processed meats
• maintaining a healthy weight
• getting 30 minutes of exercise most days
• limiting alcohol to less than 2 drinks a day
• having screening tests for bowel cancer

If you have a bowel condition such as Crohn's disease, it is important to follow your doctor's instructions to try and keep the condition under control.

Resources and support

For more about bowel obstruction or get advice on what to do next, call healthdirect on 1800 022 2221800 022 222 to speak to a nurse 24 hours, 7 days a week.

If you are concerned about bowel cancer, find out here about how to get a bowel screening test kit. You can also visit Bowel Cancer Australia for more information.

For more resources in languages other than English, you can find more information here:

• Constipation
• Healthy diet and bowels
• Watch the video: Do the bowel home screening test. It could save your life