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.

More Information


Most healthy people with cryptosporidiosis recover within two weeks without treatment.

If you have a compromised immune system, the treatment goal is to relieve symptoms and improve your immune response. Cryptosporidiosis treatment options include:

  • Anti-parasitic drugs. Medications such as nitazoxanide (Alinia) can help relieve diarrhea by attacking the parasites. Azithromycin (Zithromax) may be given with one of these medications in people with compromised immune systems.
  • Anti-motility agents. These medications slow the movements of your intestines and increase fluid absorption to relieve diarrhea and restore normal stools. Anti-motility drugs include loperamide and its derivatives (Imodium A-D, others). Talk with your doctor before using these medications.
  • Fluid replacement. Persistent diarrhea can cause you to become dehydrated. You'll need either oral or intravenous replacement of fluids and electrolytes — minerals, such as sodium, potassium and calcium, that maintain the balance of fluids in your body.
  • Antiretroviral therapies. If you have HIV/AIDS, highly active antiretroviral therapy can reduce the viral load in your body and boost your immune response. Restoring your immune system to a certain level might rid you of the symptoms of cryptosporidiosis.

Preparing for your appointment

You're likely to start by seeing your family doctor. In some cases, he or she may refer you to a doctor who specializes in infectious diseases or a doctor who specializes in disorders of the gastrointestinal tract (gastroenterologist).

Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

  • Your symptoms, including any that may seem unrelated to the reason for which you scheduled the appointment, and when the began
  • Key personal information, including recent travel, especially to other countries or to large recreational swimming areas or water parks
  • All medications, vitamins and and other supplements you take, including doses
  • Questions to ask your doctor

For cryptosporidiosis, basic questions to ask your doctor include:

  • What's the most likely cause of my symptoms?
  • Are there other possible causes?
  • What tests do I need?
  • What treatments do you recommend?
  • Are there dietary restrictions I need to follow?
  • Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you questions, such as:

  • How severe are your symptoms?
  • Does anything seem to improve your symptoms?
  • Does anything make your symptoms worse?
  • Have you been swimming recently?
  • Have you traveled out of the country recently?

What you can do in the meantime

While you're waiting to see your doctor, drink plenty of fluids.

Dec. 12, 2019
  1. Leder K, et al. Epidemiology, clinical manifestations, and diagnosis of cryptosporidiosis. https://www.uptodate.com/contents/search. Accessed Oct. 29, 2019.
  2. Parasites — Cryptosporidium (also known as "crypto"). General information for the public. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/crypto/general-info.html. Accessed Oct. 29, 2019.
  3. Cryptosporidiosis. Merck Manual Professional Version. https://www.merckmanuals.com/professional/infectious-diseases/intestinal-protozoa-and-microsporidia/cryptosporidiosis?query=cryptosporidiosis. Accessed Oct. 29, 2019.
  4. Pielok L, et al. Massive cryptosporidium infections and diarrhea in HIV-negative patients. Parasitology Research. 2019; doi:10.007/s00436-019-06302-0.
  5. Parasites — Cryptosporidium (also known as "crypto"). Prevention & control — General public. Centers for Disease Control and Prevention. https://www.cdc.gov/parasites/crypto/gen_info/prevention-general-public.html. Accessed Oct. 29, 2019.
  6. Leder K, et al. Treatment and prevention of cryptosporidiosis. https://www.uptodate.com/contents/search. Accessed Oct. 29, 2019.


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