Treatment of Diarrhea Caused by Blastocystis

Diagnosis and Treatment Considerations

The pathogenicity of Blastocystis hominis is considered clinically relevant when symptoms persist and no other pathogens are identified, according to the Infectious Diseases Society of America 1, 2

Patients who do not respond to initial treatment should be reevaluated within 24-48 hours, and alternative diagnoses such as inflammatory bowel disease or irritable bowel syndrome should be considered for symptoms persisting ≥14 days, as recommended by the Clinical Infectious Diseases guidelines 2, 3
The American Gastroenterological Association recommends ensuring adequate hydration with clear liquids (8-10 glasses daily) and avoiding products containing lactose, alcohol, and hyperosmolar supplements 3

In immunocompromised patients, a lower threshold for antimicrobial therapy should be evaluated, as suggested by the Infectious Diseases Society of America 4, 3