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

You should:

• collect your stool (faeces) sample in a clean container
• 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 stool 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 (specimen) container to use, although you can use any clean container as long as you can seal it.

Try not to collect urine or water from the toilet with the stool sample, but don't worry if you do. If you need to urinate, do this first before collecting the stool sample.

To collect a stool sample:

• label the container with your name, date of birth and the date
• place something in the toilet to catch the stool, such as a potty or an empty plastic food container, or spread clean newspaper or plastic wrap over the rim of the toilet
• make sure the sample doesn't touch the inside of the toilet
• use the spoon or spatula that comes with the container to place the sample in a clean screw-top container and 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
• put anything you used to collect the sample in a plastic bag, tie it up and put it the bin
• wash your hands thoroughly with soap and warm running water

Follow any other instructions your doctor gives you.

Storing a stool sample

Stool samples should be handed in as soon as possible, as some can't be analysed if they've been refrigerated – your doctor will tell you if this is the case.

If you can't hand the stool sample in immediately, you should store it in a fridge, but for no longer than 24 hours. Place the container in a sealed plastic bag first.

Stool samples must be fresh – if they aren't, the bacteria in them 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.

If you can't hand your stool 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.

What are stool samples used for?

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

Stools contain bacteria and other substances that are present in the digestive system.

By testing the levels of these substances and bacteria in your stools, it's possible to work out what's happening in your digestive system.

For example, a stool 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

Read the answers to more questions about operations, tests and procedures.

Further information:

• How should I collect and store a urine sample?
• Screening and testing
• Lab Tests Online UK: stool test