Diagnosis of Chronic Diarrhea in Children
How do doctors find the cause of chronic diarrhea in children?
To find the cause of a child’s chronic diarrhea, doctors may use information from the child’s medical and family history, a physical exam, or tests.
Medical and family history
Your child’s doctor will ask you for information about your child’s symptoms, such as
- how long your child has had diarrhea
- how much stool your child passes
- how often your child has diarrhea
- how your child’s stool looks, such as color and consistency
- whether your child has other symptoms along with diarrhea
The doctor will ask about the foods your child eats and beverages he or she drinks. The doctor may recommend keeping a diary of what your child eats and drinks and his or her bowel habits.
During a physical exam, a doctor typically
- checks blood pressure and pulse
- checks for symptoms of dehydration and malabsorption
- listens to sounds in your child’s abdomen using a stethoscope
- taps on your child’s abdomen to check for pain or tenderness
What tests do doctors use to find the cause of chronic diarrhea in children?
Doctors may use the following tests to help find the cause of a child’s chronic diarrhea:
Stool tests can show the presence of blood and signs of infection, food allergies, and digestive tract problems, such as malabsorption of certain sugars, proteins, or nutrients. A health care professional will give you a container for catching and storing a sample of your child’s stool, along with instructions on where to send or take the sample for testing. A doctor may also do a digital rectal exam to check for blood in your child’s stool.
A health care professional may take a sample of your child’s blood to test for signs of certain diseases or disorders that can cause chronic diarrhea, such as infections or celiac disease.
Hydrogen breath tests
This test measures the amount of hydrogen in a child’s breath. Normally, little hydrogen is found in your child’s breath. However, bacteria break down sugars—such as lactose, fructose, and sucrose—that are not digested by the small intestine and produce high levels of hydrogen. By measuring the amount of hydrogen in your child’s breath, a doctor can diagnose
- lactose intolerance
- fructose intolerance
- sucrose intolerance
- small intestinal bacterial overgrowth (SIBO)
For a lactose intolerance test, your child will drink a beverage that contains a known amount of lactose. For a fructose intolerance test, your child will drink a beverage that contains a known amount of fructose For a sucrose intolerance test, your child will drink a beverage that contains a known amount of sucrose. For a SIBO test, your child will drink a beverage that contains a known amount of sugar. Your child will then breathe into a balloon-type container that measures hydrogen. If the hydrogen level is high, your doctor will diagnose one of these disorders.
To find out if a food allergy or intolerance is causing your child’s chronic diarrhea, the doctor may recommend that your child avoid foods with lactose, carbohydrates, wheat, or other ingredients to see if a change in diet reduces or stops the diarrhea.
Your doctor may use endoscopy to look inside your child’s body to help find the cause of his or her chronic diarrhea. Endoscopic procedures include
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank:
Mark Donowitz, M.D., Johns Hopkins University School of Medicine