Acute Diarrhoea
Acute diarrhoea can be defined as passing three or more loose or watery stools a day, lasting for fewer than 14 days. It is very common, affecting almost every adult in the UK every year (although most people won’t see a doctor about it). Most cases are caused by infective gastroenteritis, which is often accompanied by vomiting and resolves on its own within 2–4 days (see Figure 43). But the GP also needs to be alert to the rarer but more serious causes of diarrhoea, such as inflammatory bowel disease, coeliac disease or bowel cancer, and infective diarrhoea needing investigation and treatment. More persistent diarrhoea may point to irritable bowel syndrome or lactose intolerance. Look out for systemic complications of diarrhoea such as dehydration, sepsis or abdominal disease.
History
- Clarify what the patient means by diarrhoea – people often use the term to mean passing normal stools frequently, or any minor change in their normal bowel habit.
- How long has the patient had diarrhoea? If more than a week this should prompt investigations to identify persistent infectious and non-infectious causes.
- Does the patient have any ideas about what has caused their diarrhoea? Have they eaten anything unusual recently, or are they in touch with people who have similar symptoms (this could suggest an infective cause)?
- Ask about recent foreign travel (raises the possibility of ‘traveller’s diarrhoea’).
- Ask about past medical history (e.g. thyroid disorders, diabetes, HIV or existing gastrointestinal conditions).
- Ask about medications, including recent treatment with antibiotics (risk of Clostridium difficile infection). Many medications (not only laxatives) have diarrhoea listed as a possible side effect.
- Ask about associated symptoms, such as abdominal pain, vomiting or blood in stools. Mild colicky abdominal cramps often accompany acute gastroenteritis, but more severe or constant abdominal pain could point to irritable bowel syndrome, diverticulitis or even an acute abdomen. Diarrhoea with vomiting is a common presentation of infective gastroenteritis, but could have another cause such as systemic illness, medication side effects or diverticulitis.
- Bear in mind the following red flags to guide further investigations or treatment:
Change in bowel habit for >6 weeks (must exclude bowel cancer)
Rectal bleeding: inflammatory bowel disease (IBD; e.g. ulcerative colitis or Crohn’s disease), colorectal cancer, some infectious causes (e.g. Campylobacter, Salmonella, Shigella, Yersinia
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
