Final answer:
Direct fecal smears can identify protozoa, bacteria, and helminths in stool samples using various staining techniques; additional tests might be required for confirmation.
Step-by-step explanation:
A direct fecal smear is a microscopic examination method used to identify various types of microorganisms present in stool samples. This examination can reveal the presence of protozoa such as Giardia, bacteria like Shigella dysenteriae, and helminths or their eggs. The identification process may involve different staining techniques like acid fast staining, Gram staining, and capsule staining to visualize specific microbial structures. While the smear provides rapid results, additional tests such as immunoassays or molecular analysis (PCR) might be necessary for confirmation. In some cases, white blood cells and blood are also observed in fecal samples, indicating infection. Severe infections could require treatment with antibiotics, though resistance to these treatments is increasingly common.