Course Diarrhea and Dehydration

Giardiasis, an intestinal infestation due to a protozoan parasite, can also cause nonbloody foul-smelling diarrhea that can be associated with chronic malabsorption. The infection may be asymptomatic or may cause abdominal cramps, epigastric pain, and flatulence. Fever is uncommon. Transmission occurs by fecal-oral route, through contaminated water (particularly surface water), from person to person, or fomites. Even a small inoculum can result in infection.

Consider treatment with metronidazole (15 mg/kg/day for 5 days) for children presenting with chronic, malabsorptive, nonbloody diarrhea without fever, as well as for patients in whom a microscopic stool exam identifies cysts or trophozoites.