Acute Invasive Diarrheal Disease (Dysentery)

Clinical definition:

Acute infection commonly caused by bacteria resulting in bloody diarrhea, often with associated fever and abdominal pain. Bacterial etiologies include Shigella flexneri, Campylobacter jejuni, enteroinvasive and enterohaemorrhagic E. coli, and non-typhoidal Salmonella species. Dysentery may also be caused by the protozoan pathogen, Entamoeba histolytica.


Preferred antibiotic choice(s)
Drug Formulation Dosage Duration
Ciprofloxacin (PO) Oral liquid: 250 mg/5 mL (anhydrous); Tablet: 250 mg (as hydrochloride) 500 mg 12 hourly 3 days
Alternative antibiotic choice(s)
Ceftriaxone (IV) Powder for injection: 250 mg; 1 g (as sodium salt) in vial 1 g 12 hourly 5 days
Azithromycin (PO) Capsule: 250 mg; 500 mg (anhydrous); Oral liquid: 200 mg/5 mL 500 mg daily 3 days
For severe cases or those progressing despite ciprofloxacin, add Entamoeba cover:
Metronidazole (PO) Injection: 500 mg in 100- mL vial; Oral liquid: 200 mg (as benzoate)/5 mL; Suppository: 500 mg; 1 g; Tablet: 200 mg to 500 mg 800 mg stat followed by 400 mg 8 hourly 7 days


Principles of Stewardship:

  • Non-bloody infectious diarrhea is generally caused by viruses and should not be treated empirically with antibiotics, but rather with supportive care and rehydration.
  • Send stool sample for culture and sensitivity prior to starting antibiotics.


  • In patients with advanced HIV and CD4 count <100 cells/mm3, consider cytomegalovirus (CMV) colitis