Infectious Colitis

Inflammation of the colon due to a microbial infection.

• Bacteria: E. coli (especially EHEC), Campylobacter, Salmonella, Shigella, Yersinia, Clostridium difficile.

• Viruses: CMV, Rotavirus, Norovirus.

• Parasites: Entamoeba histolytica, Giardia lamblia, Cryptosporidium.

• Diarrhoea, which may be bloody.
• Abdominal pain.
• Fever and chills.
• Urgency to defecate.
• Malaise.

• Signs of dehydration.

• Stool microscopy, culture, and sensitivity: Identify causative organism.

• Stool for Clostridium difficile toxin: Especially if there is a history of recent antibiotic use.

• Colonoscopy: Can help identify the site and severity of inflammation; biopsy may be taken.

• Full blood count: Elevated white cell count suggests bacterial infection.

• Hydration: Oral or intravenous rehydration.

• Antibiotics: If bacterial cause confirmed or suspected; e.g., ciprofloxacin or metronidazole. Not always necessary and can worsen certain conditions, like EHEC infections which can progress to haemolytic uraemic syndrome.

• Antiparasitic drugs: Metronidazole for Giardia or Entamoeba; nitazoxanide for Cryptosporidium.

• Supportive care.

• Hand hygiene.

• Safe food preparation and storage.

• Boil or treat water in endemic areas.

• Prophylactic antibiotics in certain high-risk scenarios (e.g., travellers to high-risk countries).

• Dehydration.

• Haemolytic uremic syndrome (HUS): Especially with EHEC.

• Perforation or toxic megacolon (rare).