Diarrhoea

Last updated 07/04/18

Definition

• Acute: <14 days
• Persistent: 14-30 days
• Chronic: >30 days
• Travellers diarrhoea

Features

• One of most common causes of death worldwide
• Particularly for children <5yrs
• Small intestine
• Watery large volume
• +/- Undigested food
• Borborygmus
• Periumbilical abdominal pain/cramps
• Large intestine
• Frequent regular small volume
• +/- Haemoatochezia
• +/- Mucus
• Tenesmus
• Lower abdominal pain
• More commonly associated with fever

Causes

• Infectious
• Acute infectious diarrhoea
• Viruses
• Most common cause
• Rotavirus
• Noravirus
• Adenovirus
• Astrovirus
• Cytomegalovirus (CMV)
• Bacteria
• More commonly the cause if more severe symptoms
• Salmonella typhi
• Campylbacter
• Shigella
• Escherichia Coli
• Clostridium difficile
• Vibrio cholera
• Protozoa
• Cryptosporidium
• Giardia
• Cyclospora
• Entamoeba
• Dysentry
• Motility disorder
• Osmotic disorder
• Secretory disorder

Associated Signs & Symptoms

• Steatorrhoea
• Haemoatochezia
• Typically indicates large intestine effected
• Commonly invasive bacteria (Salmonella, Shigella, Campylbacter), enetric viruses, Entamoeba or Clostridium difficile
• Gross frank haemotochezia: suspect enterohaemorrhagic E. Coli
• Inflammatory Bowel Disease (IBD)
• Ischaemic Colitis
• Abdominal pain
• Fever
• Nausea, vomiting

Risk Factors

Complications

• Shock

Differential Diagnosis

Investigations

• Vitals
• HR: Tachycardia: fever, hypotension: hypovolaemia, shock
• BP: hypotension: hypovolaemia, shock
• Postural hypotension: hypovolaemia
• Temp: Fever: infectious causes

Management

• Determination of source
• Assits determining causal agent
• Guides further investigation
• Assists preventing further cases/outbreak

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References

1. LaRocque R, Harris J. Approach to the adult with acute diarrhea in resource-rich settings. UpToDate. 15/11/17.