Blastocystis hominis Diagnosis and treatment
Diagnosis
Blastocystis is a group of parasites that can live in the digestive tract. Often they live there without causing harm, but sometimes they may cause symptoms.
If you have diarrhea and related symptoms, the cause may be difficult to diagnose. Even if blastocystis is found in your stool, it might not be causing your symptoms. Often another food- or waterborne organism is the cause of illness.
A healthcare professional may take your medical history and do a physical exam. You likely will be asked about recent travel and other activities. Lab tests can help diagnose parasitic diseases and other causes of gastrointestinal symptoms:
- Stool exam, also called a fecal exam. This test looks for parasites. You might receive a container with preservative fluid for your stool sample. Refrigerate the samples until you take them to the medical office or lab. Do not freeze the samples.
- Endoscopy. If the fecal exam doesn't show the cause of your symptoms, a healthcare professional might order this test. It uses a tiny camera on the end of a long, flexible tube to see into the digestive system.
- Blood tests. A blood test to check for blastocystis is available but rarely used. A healthcare professional might order blood tests to look for other causes of your symptoms.
Treatment
If you have a blastocystis infection without symptoms, you don't need treatment. Mild symptoms might go away on their own within a few days.
Medicines to get rid of a blastocystis infection and help symptoms go away might include:
- Antibiotics, such as metronidazole (Flagyl) or tinidazole (Tindamax).
- Combination medicines, such as sulfamethoxazole-trimethoprim (Bactrim).
- Antiprotozoal medicines, such as paromomycin or nitazoxanide (Alinia).
Response to these medicines can vary greatly. People with blastocystis infection also may be infected with other pathogens from contaminated food or water. These other pathogens may be the cause of the symptoms. (3p5)
Because blastocystis infection might not be the cause of your symptoms, the treatment might help symptoms go away by getting rid of another organism.
Preparing for your appointment
You may start by seeing a member of your healthcare team. Depending on your symptoms, you may see a healthcare professional who specializes in digestive system conditions, called a gastroenterologist. Or you may see a healthcare professional who specializes in infectious diseases.
What you can do
To get ready for your appointment:
- Ask if there are things you need to do in advance, such as change your diet.
- Take note of your symptoms, even if you're not sure they're related to blastocystis infection. Does anything seem to make your symptoms better or worse? Do you notice your symptoms at a certain time of day?
- Make a list of all the medicines, vitamins and other supplements that you take and the doses.
- Write down key personal information, including any major stresses or recent life changes.
- Write down questions to ask your healthcare professional.
What to expect from your doctor
Your healthcare team is likely to ask you questions, such as:
- When did you first notice your symptoms?
- How bad are your symptoms?
- Do you have symptoms all the time, or do they come and go?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
- Do you have any other health conditions?
What you can do in the meantime
If your symptoms are related to blastocystis infection, they'll likely go away on their own before you even see a healthcare professional. Stay well hydrated. Water or drinks with minerals, called rehydration solutions, may help replace fluids.
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