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, two previous CICM SAQs ( Question 11 from the first paper of 2014 and Question 13 from the second paper of 2019) asked 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.
Toxins associated with food preparation hygiene
Specific associations
Enterohaemorrhagic
|
Viral
In the returning traveller
Hospital-associated
|
Vascular causes |
|
Neoplastic causes |
|
Drug-related |
|
Idiopathic |
|
Autoimmune |
|
Surgical |
|
Endocrine |
|
Infectious |
Non-Infectious |
Viruses
Bacteria:
Parasites
Fungi
|
Immunosuppressant therapy
Consequences of BMT
ICU therapy
|
Let's say, hypothetically, that you have no idea what is causing it.
Address the possible contributing causes: these are probably not the cause of this loose motion situation, but surely these are not helping. For example:
Protect the patient from the consequences: Having diarrhoea for an ICU patient is a non-trivial issue, mainly because of how difficult it is for the nursing and allied health staff to do anything with them, but also because of the inevitable
If all else fails, one may have to resort to empirical therapies:
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; 1990.
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.
Murali, Mayur, et al. "Diarrhoea in critical care is rarely infective in origin, associated with increased length of stay and higher mortality." Journal of the Intensive Care Society (2019): 1751143719843423.
Wiesen, Patricia, Andre Van Gossum, and Jean-Charles Preiser. "Diarrhoea in the critically ill." Current opinion in critical care 12.2 (2006): 149-154.