Bacillary dysentery

Introduction to Bacillary Dysentery

Bacillary dysentery is an important cause of colonic diarrhoea in developing countries.

It is caused by pathogenic species of Shigella A-D (dysenteri, flexneri, boydii and sonnei) and transmitted through the faeco-oral route.

Clinical features of Bacillary dysentery

  • Mucoid bloody diarrhoea associated with severe central and lower abdominal pain
  • Tenesmus
  • Moderate-grade pyrexia
  • Sometimes only mild, self-limiting diarrhoea lasting for 2 to 3 days
  • Articular features occasionally
  • Septicaemic spread with multi-system involvement occasionally.

Differential diagnoses Bacillary dysentery

  • Amoebic dysentery
  • Idiopathic enterocolits (ulcerative)
  • Campylobacter jejuni infection
  • Colorectal cancer

Complications of Bacillary dysentery

  • Septicaemia/bacteraemia
  • Severe rectal bleeding
  • Intestinal perforation
  • Reiter’s syndrome


  • Stool microscopy, culture and sensitivity
  • Full Blood Count
  • Urea, Electrolytes and Creatinine

Bacillary dysentery treatment objectives

  • Adequate rehydration.
  • Eradicate bacterial pathogens

Drug treatment

  1. Oral Rehydration Therapy
  2. Parenteral hydration therapy
  3. Antibacterial drugs are not usually necessary: even diarrhoeas resulting from bacterial infection are usually self-limiting.
  4. Appropriate systemic antibiotics are however required when systemic infections occur.


  • Ciprofloxacin 500 mg to 1 g orally 12 hourly for 5 days.
  • Azithromycin 500 mg daily for 3 days for resistant strains



  • 24mg/kg 12 hourly.

Notable adverse drug reactions

Ciprofloxacin may induce tendinitis especially in children.


Ciprofloxacin is not recommended for use in children less than 18 years.
Antidiarrhoeal medicines are not advised.

Prevention of Bacillary dysentery

  • Safe drinking water
  • Sanitary disposal of human waste material

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