Diagnosis

Most cases of diarrhoea get betterwithin a week, and you may not need tovisit your GP.

The information below explains what will happen if you need to see your GP.

Read about Traveller's diarrhoea .

Identifying the cause

To identify what's causing your diarrhoea, your GP may ask you questions about:

  • what your stoolsare likefor example, if they're very watery or contain blood
  • how often you need to go to the toilet
  • whether you haveother symptoms, such as ahigh temperature (fever)
  • whether you've been in contact with anyone else who has diarrhoea, or haverecently travelled abroadthis may mean you have picked up an infection
  • whether you have recently eaten out anywherethis may mean you have food poisoning
  • whether you're taking medication andif it's recently changed
  • whether you've been stressed or anxious recently

Stool sample

Your GP may ask you for a stool sample soit can be analysedfor signs of an infection if you have:

  • persistent diarrhoea that's lasted more than two weeks
  • blood or pus in your stools
  • symptoms that affect your whole body, such as a fever or dehydration
  • a weakened immune system for example, because you have HIV
  • recently travelled abroad
  • recently been in hospital or been taking antibiotics

Find out how to collect and store a stool sample .

Blood tests

Your GP may suggest you have some blood tests if they suspectyour diarrhoea is being caused byan underlying health condition.

For example, your blood can be tested for signs of inflammation, which may suggest inflammatory bowel disease .

It can be useful for diagnosing conditions that affect your rectum and bowel.

Further investigations

If you have persistent diarrhoea and your GP is unable to find the cause, they mayrefer you to your local hospital for further investigation.

You may have:

  • a sigmoidoscopy a thin, flexible tube witha small camera and light on one (a sigmoidoscope) is inserted into your bottom andup into your bowel
  • a colonoscopy a similar procedure that uses a larger tube called a colonoscope to examine your entire bowel
Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2016