Question: How do doctors find the cause of chronic diarrhea in children?
Answer: 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 muchstoolyour 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.

Your child’s doctor may also ask about family medical history. Some of the conditions that cause chronic diarrhea, such as Crohn’s disease and ulcerative colitis, run in families.

Physical exam

During a physical exam, a doctor typically

checksblood pressureand pulse
checks forsymptoms of dehydration and malabsorption
listens to sounds in your child’sabdomenusing a stethoscope
taps on your child’s abdomen to check for pain or tenderness
Question: What tests do doctors use to find the cause of chronic diarrhea in children?
Answer: Doctors may use the following tests to help find the cause of a child’s chronic diarrhea:

Stool test

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.

Blood tests

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.

Fasting tests

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.

Endoscopy

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

colonoscopy
flexible sigmoidoscopy
upper gastrointestinal (GI) endoscopy