Clinical assessment of chronic diarrhoea

A detailed history together with a thoughtful physical examination will help to direct the diagnostic work-up and limit the number (and cost) of tests needed and increase the efficiency of the evaluation (1).

History should be able to

• establish the likelihood that the symptoms are organic (as opposed to functional)
  • presence of the following symptoms suggest an organic disease
    • history of diarrhoea of less than three months' duration,
    • predominantly nocturnal or continuous diarrhoea (as opposed to intermittent diarrhoea)
    • significant weight loss
      
      
• distinguish malabsorptive from colonic/inflammatory forms of diarrhoea
  • steatorrhoea and the passage of bulky malodorous pale stools is associated with malabsorption
  • colonic/inflammatory forms of diarrhoea typically presents with liquid loose stools with blood or mucous discharge
    
    
• assess for specific causes of diarrhoea which increase the likelihood of organic diarrhoea or point to potential lines of investigation
  • family history of neoplastic, inflammatory bowel, or coeliac disease.
  • previous surgery leading to malabsorption
  • previous pancreatic diseases
  • systemic illness - thyrotoxicosis and parathyroid disease, diabetes mellitus etc
  • alcohol
  • drugs
  • recent overseas travel
  • recent antibiotic therapy and Clostridium difficile infection
  • change in diet - excessive fibre and misuse of laxatives will increase the frequency of stools.
  • lactase deficiency

Physical examination may reveal underlying cause for diarrhoea:

• recent weight loss or lymphadenopathy - chronic infection or malignancy.
• episcleritis - inflammatory bowel disease (IBD)
• exophthalmia - hyperthyroidism
• Dermatitis herpetiformis - seen in 15-25% of patients with celiac disease
• abdominal examination
  • scars - surgical cause of diarrhoea
  • bowel sounds - hypermotility
  • tenderness - infection and inflammation
  • masses - neoplasia
• rectal examination - to exclude any induration or local tenderness that might suggest Crohn's or an anal fissure

Reference:

1. Arasaradnam RP, Brown S, Forbes A, et al. Guidelines for the investigation of chronic diarrhoea in adults: British Society of Gastroenterology, 3rd edition. Gut. 2018 Aug;67(8):1380-99.