Diagnosis

The following tests can diagnose cryptosporidium infection:

• Acid-staining test. To get cells for the analysis, your doctor might ask for a stool sample or, possibly, take a tissue sample (biopsy) from your intestine. The sample is then looked at under a microscope.
• Stool culture. A culture of a sample of your stool can't detect cryptosporidium, but it can help rule out other bacterial pathogens.
• Other tests. Once it's clear that your infection is caused by cryptosporidium parasites, you might need further testing to check for complications. For example, checking liver and gallbladder function might determine whether the infection has spread.