The written paper (as well as clinical life in general) occasionally gives us cause to generate a broad list of differentials for diarrhoea.

For instance, Question 11 from the first paper of 2014 asks about the potential causes of diarrhoea in a septic bone marrow transplant recipient.

If one has no access to the distilled wisdom of UpToDate, one can find some solace in review articles such as this one from 2009 (Gastroenterology), in book chapters such as Timothy Woods' piece for Clinical Methods, or in short pithy summaries such as this pearl from the LITFL.

Generally speaking, the author has never found the osmotic/exudative distinction to be particularly helpful. The causes below are organised according to a totally arbitrary scheme.

Infectious Causes of Acute Diarrhoea in Adults

Toxins associated with food preparation hygiene

  • Staphylococcus
  • Clostridium perfringens

Specific associations

  • Vibrio vulnificus - shellfish/seafood
  • Yersinia - milk
  • Bacillus cereus - rice
  • Salmonella - poultry


  • Shigella
  • Salmonella
  • Campylobacter
  • E.coli


  • Rotavirus
  • Norovirus
  • Adenovirus
  • Cytomegalovirus


In the returning traveller

  • Giardia
  • Cryptosporidium
  • Entamoeba histolytica
  • Vibrio cholerae


  • Clostridium difficile
  • Neutropenic enterocolitis
Non-Infectious Causes of Diarrhoea in Adults
Vascular causes
  • Ischaemic gut / ischaemic colitis
  • Upper GI bleeding (the laxative effect of blood)
Neoplastic causes
  • Villous adenoma
  • Gastric carcinoma (gastrinoma/VIPoma)
  • Colonic polyps and tumours with partial obstruction (overflow)
  • Antibiotic-associated
  • Lactulose
  • Colchicine
  • Cytotoxic agents
  • Neostigmine and other pro-motility agents
  • Opioid withdrawal
  • Irritable bowel syndrome
  • Hyperosmolar nasogastric feeds
  • Lactase deficiency
  • Hypoalbuminaemia
  • Graft vs host disease
  • Inflammatory bowel diseases:
    • Crohns
    • Ulcerative colitis
  • Malabsorption-related
    • Coeliac disease
  • Short gut syndrome
  • Radiation colitis
  • Carcinoid syndrome (serotonin overproduction)
  • Hyperthyroidism


Causes of Diarrhoea in the Bone Marrow Transplant Recipient




  • Rotavirus
  • Norovirus
  • Adenovirus
  • Cytomegalovirus


  • Clostridium difficile
  • Shigella
  • Salmonella
  • Campylobacter
  • E.coli
  • Aeromonas


  • Giardia
  • Cryptosporidium
  • Microsporidium


  • Candida


Immunosuppressant therapy

  • Cytotoxic drugs
  • Tacrolimus
  • Whole-body irradiation

Consequences of BMT

  • Neutropenic enterocolitis
  • Graft vs host disease

ICU therapy

  • Pro-motility agents
  • High caloric feeds
  • Lactulose
  • Opioid withdrawal
  • Broad spectrum antibiotics


UpToDate have a good article on acute diarrhoea for the paying customer.

Kelly, T. W. J., M. R. Patrick, and K. M. Hillman. "Study of diarrhea in critically ill patients." Critical care medicine 11.1 (1983): 7-9.

Wiesen, Patricia, Andre Van Gossum, and Jean-Charles Preiser. "Diarrhoea in the critically ill." Current opinion in critical care 12.2 (2006): 149-154.

Ferrie, Suzie, and Vivienne East. "Managing diarrhoea in intensive care."Australian Critical Care 20.1 (2007): 7-13.

Pawlowski, Sean W., Cirle Alcantara Warren, and Richard Guerrant. "Diagnosis and treatment of acute or persistent diarrhea." Gastroenterology 136.6 (2009): 1874-1886.

Schiller, Lawrence R. "Diarrhea." Medical Clinics of North America 84.5 (2000): 1259-1274.

Timothy A. Woods. "Diarrhea." Chapter 88 in: Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths.

Guerrant, Richard L., et al. "Practice guidelines for the management of infectious diarrhea." Clinical infectious diseases 32.3 (2001): 331-351.

Cox, George J., et al. "Etiology and outcome of diarrhea after marrow transplantation: a prospective study." Gastroenterology 107.5 (1994): 1398-1407.