Diarrhoea is likely to settle within a week and you may not need to see your GP for a diagnosis. See Diarrhoea - symptoms for more information about when to contact your GP.
The below information explains what will happen if you need to see your GP.
Diagnosing the cause
To diagnose the cause of your diarrhoea, your GP may ask a number of questions, such as:
- what your faeces are like – for example, if they are very watery or contain blood
- how often you have had diarrhoea
- what other symptoms you have, such as fever
- whether you have been in contact with anyone else who has diarrhoea (as you may have caught an infection)
- whether you have eaten out anywhere (as you may have food poisoning)
- whether you have recently travelled abroad (to rule out travellers’ diarrhoea)
- what medication you are taking and if this has recently changed
- whether you have been stressed or anxious
- how much alcohol you drink
Stool sample
Your GP may ask for a stool sample to investigate for bacteria or parasites if you have:
- persistent diarrhoea lasting more than a week
- other symptoms, such as blood or pus in your stools
- symptoms that affect your whole body, such as fever or dehydration
- a weakened immune system, for example because you have HIV
- recently travelled abroad
- recently been in hospital or been taking antibiotics
For information about providing a stool sample, see How should I collect and store a stool sample?
Blood tests
Your GP may suggest blood tests if an underlying health condition is possibly causing your diarrhoea. For example, your blood can be tested for signs of inflammation, which may suggest an inflammatory bowel disease. See Diarrhoea - causes for more information.
Rectal examination
If you have unexplained persistent diarrhoea, or if you are over 50 years old, your GP may suggest a digital rectal examination. During a digital rectal examination, your GP inserts their finger into your anus (back passage) and rectum. It can be useful in diagnosing conditions that affect your rectum and bowels.
Referral
Your GP may need to refer you to your local hospital for further investigations to identify the cause. For example, you may have:
- a sigmoidoscopy – a procedure that involves inserting a sigmoidoscope (a thin, flexible tube attached to a small camera and light) into your rectum then up into your bowel
- a colonoscopy – a similar procedure that uses a larger tube, called a colonoscope, to examine your entire bowel
