How should I collect and store a poo (stool) sample?

Your GP or another healthcare professional may ask you for a stool sample to help them diagnose or rule out a particular health condition.

Poo contains bacteria and other substances that are in the digestive system. By testing the levels of these substances and bacteria in your poo, it’s possible to work out what’s happening in your digestive system.

For example, the sample can be tested to help diagnose:

  • gastroenteritis – a common condition that causes diarrhoea and vomiting, and is usually the result of a bacterial or viral tummy bug
  • inflammatory bowel disease – such as Crohn’s disease, a condition that causes inflammation of the lining of the digestive system, and ulcerative colitis, a condition where the colon and rectum become inflamed.

You should collect your poo (stool) sample in a completely clean (sterile) container.

You should store the container in a fridge in a sealed plastic bag if you can’t hand it in straight away.

Collecting a stool sample

Your GP or another healthcare professional, such as a nurse, should explain how to collect the sample. It should be collected in a clean, dry screw-top container.

Your doctor or a member of staff at the hospital will give you a plastic container (also known as a specimen container) to use. Please do not use any other container. Try not to collect pee (urine) or water from the toilet along with the poo, but don’t worry if you do. If you need to pee, do this first before collecting the poo.

Follow these steps

  • Label a clean, screw-top container with your name, date of birth and the date.
  • Place something in the toilet to catch the poo, such as a potty or an empty plastic food container such as a clean ice cream container, or spread clean newspaper or plastic wrap over the rim of the toilet.
  • Ask for help from a household member or your carer if you need assistance.
  • Make sure the poo doesn’t touch the inside of the toilet.
  • Use the spoon or spatula that comes with the container to collect the poo, then screw the lid shut
  • If you’ve been given a container, aim to fill around a third of it – that’s about the size of a walnut if you’re using your own container.
  • If you have been asked to provide a sample of your diarrhoea (runny poo) to test for gastro-enteritis (upset gut) aim to fill around a third of the container:
    • make sure you scoop the runny poo rather than the easy-to-pick-up hard lumps 
    • diarrhoea is defined as runny poo that is soft enough when collected to take the shape of the container
    • any poo sample requested for tests as a result of an upset gut, that is of hard consistency will not be tested by the lab, so ensure that the poo sample is of the right runny/soft consistency.
  • After taking your sample, put anything you used to collect the poo in a plastic bag, tie it up and put it the dustbin. 
  • Wash your hands thoroughly with soap and warm running water.
  • Follow any other instructions your doctor has given you.

Storing a stool sample

Your sample of poo must be fresh – if it is not, the bacteria in it can multiply. This means the levels of bacteria in the stool sample won’t be the same as the levels of bacteria in your digestive system. If the levels of bacteria don’t match, the test results may not be accurate.

Your sample should be handed in as soon as possible, as sometimes it can’t be analysed after being refrigerated – your doctor will tell you if this is the case.

If you can’t hand your sample in immediately, find out how long it can be kept in the fridge. Your GP or the healthcare professional who requested the test will be able to tell you. If you can store it in the fridge, put the container in a sealed plastic bag first.