Macroscopic Examination

If the stool consistency can be determined it may give an indication of the types or stages of organisms present. Trophozoites (motile forms) of the intestinal protozoa are usually found in liquid specimens; both trophozoites and cysts might be found in a soft specimen. Cyst forms are generally found in formed specimens; however, there are always exceptions to these general statements. Coccidian oocysts and microsporidian spores can be found in any type of fecal specimen; in the case of coccidian oocysts, the more liquid the stool, the more oocysts that are found in the specimen. Helminth eggs may be found in any type of specimen, although in a liquid stool the chances of finding eggs are reduced by the dilution factor. Tapeworm proglottids may be found on or beneath the stool on the bottom of the collection container. Adult pinworms and Ascaris lumbricoides may occasionally be found on the surface or in the stool.