Anti-Antibody to *Giardia lamblia* (IgA, IgG) – Immunoassay

This test checks a stool sample for Giardia, a tiny parasite that infects the intestines and causes diarrhea. Your doctor may order it if you have ongoing stomach upset, loose stools, or possible exposure through unsafe water, travel, or close contact with an infected person. Finding the parasite helps your care team confirm the cause of your symptoms and choose the right treatment.

Your healthcare provider may order this test if you have symptoms like persistent diarrhea, bloating, or stomach pain that could be linked to a parasite infection. It may also be used if you’ve traveled to areas with higher risk for *Giardia* exposure or if you’ve been in close contact with someone who has an infection.

No special preparation is usually needed, but your doctor may give specific instructions, such as avoiding certain medicines like antacids or anti-diarrheal drugs for a short time before the sample is collected. You will be asked to provide a small stool sample in a clean container, either at home or at the lab. Follow the collection steps carefully and wash your hands well afterward.

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The test measures antibodies (IgA or IgG) produced by your immune system in response to *Giardia lamblia*, which can indicate past or current infection.

A positive result means Giardia parasites or their proteins were found in your sample, confirming an active infection that can usually be treated with prescription medicine. A negative result usually means the parasite was not detected, but if symptoms continue, your doctor may repeat the test because the parasite is not shed in every stool sample. Your care team will explain your results and discuss next steps with you.

Positive results suggest your body has detected *Giardia lamblia* antibodies, possibly from past infection. Negative results mean no detectable antibodies were found in this test. Remember, antibodies alone don’t confirm an active infection—your provider may recommend additional testing (like stool samples) for diagnosis.

Giardia infection often causes watery or greasy diarrhea, stomach cramps, bloating, and gas. Some people feel nauseated, lose their appetite, or lose weight because the parasite interferes with the body's ability to absorb nutrients and fat. Symptoms usually begin one to two weeks after exposure and may last several weeks, and some infected people have no symptoms at all.

Symptoms may include watery diarrhea, stomach cramps, bloating, gas, nausea, or weight loss. Some people may not have symptoms at all, especially children or those with weakened immune systems.