A blocked bowel (bowel obstruction)

A bowel obstruction means there is a blockage in the bowel. It is a serious complication, which is more common with ​advanced cancer​ .

About bowel obstruction

Your bowel might become completely or partially blocked. This means that the waste from digested food can't get past the blockage. The diagram shows the bowel and the rest of the digestive system.

Bowel obstruction can happen when:

• cancer in the abdominal area presses on the bowel such as ovarian, bowel or stomach cancer

• other cancers such as lung or breast cancer spread to the abdomen and presses on the bowel

• cancer grows into the nerve supply of the bowel and damages it - this can stop the muscles working

• a solid mass of indigestible material collects in the bowel

People who have had surgery or radiotherapy to the tummy (abdomen) are more at risk of developing a bowel obstruction.

Symptoms of bowel obstruction

The symptoms include:

• feeling bloated and full

• pain, that is usually a colicky tummy pain

• feeling sick

• vomiting large amounts, including undigested food or bowel fluid

• not opening your bowels or passing wind (constipation)

• absent or abnormal bowel sounds

• diarrhoea, this is usually in people who have a partial obstruction

Diagnosing a bowel obstruction

Your doctor or nurse will examine you and ask you questions. They will then arrange some tests and investigations. These might include blood and urine tests.

You may also have:

• a ​CT scan​

• an abdominal x-ray

Your doctor might also arrange for other scans such as an ​MRI scan​ or ​ultrasound scan​ . They will tell you more about the tests you will need. 

Read about tests and scans

Treating a bowel obstruction

It’s important to understand what your doctors are trying to achieve with any treatments they recommend. So talk it through with them or with your specialist nurse.

Treatments for a blocked bowel can include:

Drips and drains

Your doctor might suggest treatment to give your bowel time to rest. To do this you stop eating and drinking until your bowel is working normally again. You usually have fluids through a drip so you don’t get dehydrated. This is called an intravenous infusion.

Sometimes you can have an infusion of fluids at home. You have this through a fine needle put just under the skin, instead of into a vein.

This may fix the blockage. But if it isn’t successful, you may need other treatments.

You might have a tube that goes up your nose and down into your stomach. This is called a nasogastric tube. This drains fluid from your stomach and stops you feeling sick.

Some people might have a venting gastrostomy tube to help relieve nausea and vomiting. This tube is called a percutaneous endoscopic gastrostomy tube or PEG tube. The tube goes into your stomach through an opening made on the outside of your tummy. You usually have this under ​sedation​ .

Find out more about feeding tubes

Surgery to unblock the bowel

If your cancer is advanced and cannot be cured, your doctor might suggest surgery to offer you longer term relief from your symptoms. The surgeon removes enough of the cancer to unblock the bowel. They might remove part of the bowel as well. 

After the operation, your surgeon is most likely to repair the bowel by stitching the ends back together. But sometimes it isn’t possible to do this and you may need to have a ​colostomy​ or ​ileostomy​ (stoma). A stoma is an opening from the bowel onto the abdomen. Your poo comes out of this opening into a plastic bag that sticks over it.

Find out about having a stoma

Deciding whether to have an operation like this can be difficult. 

The surgery won't cure your cancer. But it can relieve the symptoms that you have. Unfortunately, no one can tell you beforehand how much you will benefit from an operation to unblock your bowel.

The operation could be successful and the cancer might not grow back to block the bowel again. But it is quite a big operation to have when you are likely to be feeling very weak and ill.

You might want to talk through having this operation with your close family and friends as well as your doctor and nurse.

Surgery to put in a stent

A stent is a tube that the surgeon puts into the bowel. It expands to keep the bowel open. This can relieve the symptoms caused by the obstruction.

Your surgeon may be able to put in a stent if you are not able to have a big operation. 

Having a stent

The surgeon puts a tube with a light at the end (colonoscope) into your bowel through the back passage (rectum). This is called a colonoscopy.

The surgeon uses the colonoscope to see where the blockage is and pushes a stent through it. The stent expands and holds the bowel open so poo can pass through again. The stent stays in place to keep the bowel open. It relieves symptoms and gives your surgeon time to plan surgery to remove the blocked part of the bowel. 

Medicines to help control symptoms

Instead of an operation, medicines can sometimes help to control symptoms of a blocked bowel. Unfortunately, these types of treatment will usually only control your symptoms for a while.

You usually have painkillers and anti sickness medicines.

You might have a drug called octreotide to control sickness. Octreotide works by slowing down or stopping the body producing a number of ​hormones​ and chemicals. These include gut hormones which control the emptying of the stomach and bowel. Octreotide reduces the amount of fluid that builds up in your stomach and ​digestive system​ . .

Hyoscine butylbromide, also known as Buscopan, is a medicine that can help stop muscle spasms and relieve tummy pain.

​Steroids​ can help to reduce the ​inflammation​ of your bowel. They can also help to control sickness and pain. 

Read more about bowel problems in people with cancer