Managing bowel problems caused by pancreatic cancer

Many people with pancreatic cancer will notice changes to their poo, including diarrhoea and constipation.

What bowel problems do people have?

Bowel problems may include:

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

Some people also get problems such as wind, bloating, and need to empty their bowels urgently, especially after eating. These can be caused by problems digesting food.

Bowel problems can also be a symptom of pancreatic cancer before it’s diagnosed. Read more about symptoms.

Speak to your doctor or nurse about any bowel problems. They can work out what is causing them, and find ways to manage them.


Constipation (when you find it hard to poo) can be a side effect of some treatments. For example, opioid painkillers like morphine can cause constipation. Not moving around much, not eating much, and dehydration, may also make constipation more likely. Constipation can be very uncomfortable, and can cause bloating and sickness.

Laxatives are medicines used to treat and prevent constipation. If you are taking opioid painkillers, you should be given laxatives to prevent this.

Try to drink plenty of fluids to help reduce constipation. Eating regularly may also help.


Some people get a symptom called steatorrhoea, which is pale poo that floats and smells horrible. This happens if the body can’t digest the fat in food properly. Taking pancreatic enzymes can help with steatorrhoea.


Diarrhoea (runny poo) can be caused by problems digesting food, an infection or some types of chemotherapy. If the diarrhoea is caused by problems digesting food, taking pancreatic enzymes can help. Find tips for managing diarrhoea.

Some people have ongoing diarrhoea that isn’t helped by enzymes. 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 the doctor, nurse or GP if your diarrhoea isn’t getting better. You may need to see a gastroenterology team, who are experts in problems with the stomach and intestines. There are tests that can be done to check for bile acid diarrhoea and SIBO, and medicines to treat them.

What is dehydration?

Dehydration happens when the body loses more water than it takes in. It might happen if you are sick a lot and can’t keep down any food or water, or if you have diarrhoea (runny poo).

Signs of dehydration include dark or strong smelling urine (pee) and passing less urine. It can also cause headaches, feeling thirsty and feeling dizzy or light headed.

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

Questions about bowel problems?

If you have questions about any bowel problems and how to manage them, speak to your doctor or nurse.

You can also speak to our specialist nurses on our free Support Line.

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Specialist nurse Rachel

Updated October 2021

Review date October 2023