Helicobacter pylori (H. pylori) bacteria are a common cause of peptic ulcers (sores in the lining of the stomach, small intestine, or esophagus). In this test, a stool (feces) sample is used to determine if H. pylori antigens are present in your child's gastrointestinal (GI) system. Antigens are substances that trigger the immune system to fight infection.
A doctor may request an H. pylori antigen stool test if your child has symptoms that could indicate the presence of a peptic ulcer, such as indigestion, abdominal pain, a full or bloated feeling, nausea, frequent belching, or vomiting. A test also might be ordered after your child completes a course of antibiotics for H. pylori to determine whether it eradicated the infection.
Unlike most other lab tests, a stool sample is often collected by parents at home, not by health care professionals at a hospital or clinic. For 2 weeks before the test, your child may be asked to avoid certain medications such as antibiotics, antacids, bismuth, and peptic ulcer medicines such as proton pump inhibitors (PPIs) and H2 blockers.
The doctor or hospital laboratory usually will provide written instructions on how to collect a stool sample. If instructions aren't provided, here are tips for collecting a stool sample from your child:
Alternatively, a doctor or nurse may collect a small stool sample by inserting a swab into your child's rectum.
When the sample arrives at the laboratory, a small amount of stool is placed in tiny vials. Specific chemicals and a color developer are added. At the end of the test, the presence of a blue color indicates the presence of H. pylori antigens.
In general, the result of the H. pylori stool test is reported in 1-4 days.
No risks are associated with collecting stool samples.
Collecting a stool sample is painless. Tell your child that collecting the stool won't hurt, but it has to be done carefully. A child who's old enough might be able to collect the sample alone to avoid embarrassment. Tell your child how to do this properly. If the sample is collected by swabbing, your child may feel slight pressure in his or her rectum during the procedure.
If you have questions about the H. pylori stool test, speak with your doctor.