Dysentery: causes, symptoms, treatment, and prevention

Causes and diagnosis

Two broad groups of organisms commonly cause dysentery: invasive bacteria (for example, species in the genus Shigella and certain strains of Salmonella or Campylobacter) and protozoan parasites such as Entamoeba histolytica. The appropriate therapy depends on identifying the cause. Diagnosis is generally made by clinical assessment combined with stool testing: microscopic examination, culture, or antigen/PCR tests may be used to detect the pathogen.

Symptoms and possible complications

Typical symptoms include:

• Frequent diarrhoea containing blood or mucus
• Lower abdominal pain and cramping
• Fever and general malaise
• Urgency or tenesmus (feeling of incomplete evacuation)

Complications can be serious, especially in young children, older adults and people with weakened immune systems. Dehydration is the immediate danger; more severe outcomes include spreading infection, prolonged intestinal damage or, in amoebic disease, liver abscesses.

Treatment

Initial management focuses on fluid and electrolyte replacement to prevent or treat dehydration. Definitive therapy depends on the cause: bacterial dysentery may respond to antibiotics while amoebic dysentery requires antiparasitic medications; clinical guidelines and local resistance patterns should guide drug choice. For information about antimicrobial options see antibiotic guidance. Supportive care includes rest, nutritional support and monitoring for complications.

Prevention and public health

Prevention emphasises access to clean water, safe sanitation, good hand hygiene and careful food handling. Outbreaks are common where sanitation is poor, in crowded settings or after natural disasters. Vaccines are not widely available for most causes, so public-health measures and rapid case management remain the principal ways to reduce illness and transmission.