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Changes to bowel habits

Many people with pancreatic cancer will notice changes in their bowel habits. These may include:

  • problems emptying the bowels (constipation)
  • pale, oily poo that floats, smells horrible and is difficult to flush down the toilet (steatorrhoea)
  • runny poo (diarrhoea).

Speak to your doctor or nurse if any bowel problems don’t get better, or get worse. They can work out what is causing them, and find ways to manage them.


Constipation can be very uncomfortable, and can cause bloating and sickness. Opioid painkillers, like morphine, can cause constipation. You should be given medicines called laxatives to take with opioids to prevent this. Not moving around or eating much, or being dehydrated, can also make constipation more likely.


Some people get a symptom called steatorrhoea, which is pale poo that floats. This happens if your body can’t digest fat in your food properly – because the pancreas isn’t producing enough enzymes. Taking pancreatic enzyme supplements can help to relieve steatorrhoea.


Diarrhoea can have different causes, including the cancer, some treatments such as chemotherapy, some medicines, or an infection. It can cause dehydration quite quickly, so it is important to drink plenty of water to prevent this. Speak to your doctor or nurse if you have diarrhoea several times a day. They can look at what’s causing this, and how to manage it.

Diarrhoea can be caused by problems digesting food, and pancreatic enzyme supplements may help with this. If you haven’t been told about enzyme supplements, speak to your doctor or nurse about this.

Some people have ongoing diarrhoea that isn’t helped by enzyme supplements. If you have diarrhoea that isn’t getting better, you may have bile acid diarrhoea – which can happen if there is too much bile in the intestine. Or you may have small intestinal bacterial overgrowth (SIBO), which is caused by having too much bacteria in the intestines.

Speak to your medical team if you have diarrhoea that isn’t getting better. There are tests that can be done to check for bile acid diarrhoea and SIBO, and medicines to treat them. You may need to see a gastroenterology team, who are experts in problems with the stomach and intestines.

What is dehydration?

Dehydration happens when the body loses more water than it takes in. It might happen if someone is sick a lot and can’t keep down any food or water, or if they have diarrhoea.

Signs of dehydration include:

  • dark coloured or strong smelling urine (pee)
  • passing less urine
  • headaches
  • feeling thirsty
  • and feeling dizzy or light headed.

If you have any signs of dehydration, tell your doctor or nurse. Dehydration needs treating to make sure it doesn’t become a serious problem. Dehydration may be more serious if someone has diabetes.

Read about other symptoms and side effects and how they can be managed.

Updated September 2019

Review date September 2021

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