The most common form of diarrhoea is caused by a protozoan called Blastocystis hominis. The organism can cause a variety of symptoms, including fever, abdominal pain, and abdominal cramps. Stool examinations can identify Blastocystis spp. by their vacuolar, granular, or cystic forms. The organism’s iodine staining may also identify this pathogen.
Stool cultures of Blastocystis spp. are the only way to determine whether a patient has Blastocystosis infection. PCR tests are a popular method, and they are more accurate than culture tests. However, they take time to perform. These results are unreliable, and it takes a few days for the results to become available.
In a simple stool smear, Blastocystis is not particularly noticeable. Its size varies from six to 40 mm, but it is a nondescript parasite. Its central body is similar to a vacuole and pushes nuclei out of the cell, acting as a reservoir for proteases and possibly serving other functions.
The pathogenicity of Blastocystis spp. is largely unknown. The US Pubmed database contains only 16 reports of infection. The authors’ review of these cases showed that the majority of them were not positive. Most positive results, however, were reported by other researchers, and this further supports the theory that these techniques do not work well for detecting Blastocystis sp.
While stool microscopy is the most commonly used method, culture is a reliable and sensitive method. It takes two to three days to detect a single Blastocystis sp., which is the most common type of infection in this disease. In a smaller study of patients from Oregon, a subtype of the organism was identified in the stool samples.
The laboratory findings from stool examination in blastocystis diarrhea are primarily based on bacterial species. In addition to a clinical diagnosis, a positive result may indicate that the patient is suffering from the disease. The infection may be characterized by a bacterial flora spp. Among these, a gram-negative organism is most likely to be present.
Other stool tests may also reveal Blastocystis spp. in stool samples of UC patients. In those with IBD, the presence of Blastocystis sp. in the stool may be associated with symptoms of the disease. The results of the stool examinations can be useful in determining whether the condition is caused by a bacterial infection.
In some cases, a symptomatic patient may be infected with Blastocystis in asymptomatic form. In such cases, the bacterial pathogen can be found by analyzing the fecal contents. In addition, a bacterial fecal IgA test can also differentiate asymptomatic patients from those with symptoms of the disease.