This is because in unpreserved feces, the morphological characteristics of the trophozoites do not persist, and will round up and become granular within 15 minutes at room temperature. Collect stool samples on alternate days since D fragilis can be excreted in a cyclic pattern similar to Giardia lamblia . The final portion of the stool evacuation may contain the most concentrated numbers of trophozoites. Collect stool specimens before radiological procedures that employ barium because barium interferes with trophozoite detection and may do so for several weeks. Other medications that can interfere with parasite detection are antibiotics, antiprotozoan medications, antimalarials, mineral oil, bismuth-containing preparations, and nonabsorbable diarrheal medications.
Multinucleated forms can also be present.
The cytoplasm frequently contains numerous food vacuoles. The goal of therapy is eradication of the parasite. The drugs used are considered investigational by the Food and Drug Administration because of a lack of clinical trials. Pregnancy B - Usually safe but benefits must outweigh the risks. Examination of stool specimens 3-4 weeks after therapy to determine if the parasite was eliminated should be considered.