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This summary has been developed for use by community pharmacists under our Guidelines for Pharmacy title and therefore only covers the information relevant to this setting. For community pharmacists, the referral section implies primary care referral prior to secondary care referral. Please see the full guideline for the complete set of recommendations.

How should I assess a person with acute diarrhoea?

  • Determine the onset, duration, frequency, and severity of symptoms
  • Enquire about the presence of red flag symptoms:
    • blood in the stool
    • recent hospital treatment or antibiotic treatment. For more information, see the CKS topic on diarrhoea—antibiotic associated
    • weight loss
    • evidence of dehydration
    • nocturnal symptoms—organic cause more likely
  • Attempt to ascertain the underlying cause. Assess for:
    • quantity and character of stools (watery, fatty, containing blood or mucus)
    • features suggesting infection, such as:
      • fever
      • vomiting
      • recent contact with a person with diarrhoea
      • exposure to possible sources of enteric infection (for example, having eaten meals out, or recent farm or petting zoo visits)
      • travel abroad — increases the likelihood of infection. Ask about potential exposures such as raw milk or untreated water
      • being in a higher risk group such as food handlers, nursing home residents, and recently hospitalized people
    • any new drugs, especially antibiotics or laxatives
    • stress or anxiety
    • abdominal pain, which is often present in inflammatory bowel disease, irritable bowel syndrome, and ischaemic colitis
    • history of recent radiation treatment to the pelvis
    • factors increasing the risk of immunosuppression (for example, human immunodeficiency virus infection, long term steroid use, or chemotherapy)
    • any surgery or medical conditions (for example, endocrine disease) accounting for the diarrhoea
    • diet and use of alcohol or substances such as sorbitol
  • Assess for complications of diarrhoea, such as dehydration
    • features indicating dehydration include increased pulse rate, reduced skin turgor, dryness of mucous membranes, delayed capillary refill time, decreased urine output, hypotension (check for postural changes), and altered mental status. For more detail, see clinical features of dehydration
    • also consider underlying conditions that may increase the risk of complications
  • If acute causes have been excluded and the person has features suggestive of an early presentation of a chronic cause, see Scenario: Chronic diarrhoea (more than 4 weeks)

Clinical features of dehydration

  • Mild dehydration
    • lassitude
    • anorexia, nausea
    • light-headedness
    • postural hypotension
    • usually no signs
  • Moderate dehydration
    • apathy/tiredness
    • dizziness
    • nausea/headache
    • muscle cramps
    • pinched face
    • dry tongue or sunken eyes
    • reduced skin elasticity
    • postural hypotension
    • tachycardia
    • oliguria
  • Severe dehydration
    • profound apathy
    • weakness
    • confusion, leading to coma
    • shock
    • tachycardia
    • marked peripheral vasoconstriction
    • systolic blood pressure less than 90 mmHg
    • oliguria or anuria

When should I admit or refer a person with acute diarrhoea?

  • Arrange emergency admission to hospital if:
    • the person is vomiting and unable to retain oral fluids, or
    • they have features of severe dehydration or shock
  • Other factors that influence the threshold for admission include (use clinical judgment):
    • older age (people 60 years of age or older are more at risk of complications)
    • home circumstances and level of support
    • fever
    • bloody diarrhoea
    • abdominal pain and tenderness
    • increased risk of poor outcome, for example:
      • coexisting medical conditions—immunodeficiency, lack of stomach acid, inflammatory bowel disease, valvular heart disease, diabetes mellitus, renal impairment, rheumatoid disease, systemic lupus erythematosus
      • drugs—immunosuppressants or systemic steroids, proton pump inhibitors, angiotensin-converting enzyme inhibitors, diuretics
  • Refer adults using a suspected cancer pathway referral (for an appointment within 2 weeks) for colorectal cancer if:
    • they are aged 40 and over with unexplained weight loss and abdominal pain, or
    • they are aged 50 and over with unexplained rectal bleeding, or
    • they are aged 60 and over with iron deficiency anaemia or changes in their bowel habit, or tests show occult blood in their faeces
  • Consider a suspected cancer pathway referral (for an appointment within 2 weeks) for colorectal cancer in:
    • adults with a rectal or abdominal mass
    • adults aged under 50 with rectal bleeding and any of the following unexplained symptoms or findings:
      • abdominal pain
      • change in bowel habit
      • weight loss
      • iron-deficiency anaemia

© NICE 2018. NICE CKS on diarrhoea—adult’s assessment. Available from: cks.nice.org.uk/diarrhoea-adults-assessment. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication. 

Last updated: December 2018.