Definitions of the term “diarrhoea” can vary significantly. Some describe it as increased fluidity of the stools, and this may be quantified with scales such as the Bristol Stool Score. Scientifically, it can be described as more than 200g of stools per day. However, individuals on a high-fibre diet may experience volumes greater than this with normal stool consistency. Faecal incontinence may be confused with diarrhoea, but may also co-exist. These factors need to be taken into consideration when investigating this symptom.

There are a multitude of causes for diarrhoea – some benign, other more serious. Your physician should establish, through careful history-taking and examination, what is the most likely cause of your diarrhoea. Initial investigations may include blood tests and stool examination. Endoscopy may be required if a cause is not found using non-invasive methods.

The nature of the stools can provide useful information to your physician. It is important to note certain points, for example the presence of blood or mucus, or whether the stools are watery or greasy. The volume and frequency of stools are of great significance also.

Diarrhoea is classified as chronic when it persists for greater than four weeks. Acute diarrhoea is most often caused by infections (e.g. food poisoning, viruses, bacteria) and these are usually self-limiting.

Common causes of chronic diarrhoea include: