More than one-third of all kids will at some point complain of a persistent stomachache. Parents come to expect a degree of before-school bellyaching or basic bugs that come and go in a short time—but when is it time to address chronic stomach pain?

Recurring stomachaches, while distressing and disruptive, usually don't indicate a serious underlying medical problem, but instead fall into the category of functional abdominal pain, says Dr. David Ziring, associate director of the Pediatric Inflammatory Bowel Disease Program at Cedars-Sinai Guerin Children's. A pediatrician or a gastroenterologist can listen carefully to determine the nature and circumstances of the pain, rule out more concerning causes and help your child feel well again.

See a physician if your child complains of chronic abdominal pain—aches, cramps, bloating, gas or nausea—for more than two weeks. Seek immediate attention if your child's pain is accompanied by abnormal weight loss, loss of appetite, unexplained fever, vomiting, diarrhea, blood in the stool or joint pain—concerns that should be evaluated and treated right away.

"Parents should always bring their children to the doctor when they're concerned, but these red flags are more likely to indicate a problem that requires further investigation and intervention," Dr. Ziring says.

Generally, pain centered around the belly button is less worrisome—abdominal pain further from the belly button is more likely to indicate a condition of significant concern, Dr. Ziring says.  Doctors will evaluate the location of the pain and take a very detailed medical history for your child, including a family history of inflammatory bowel disease (IBD), as they search for the cause of the pain.

Read: Is It IBS or IBD?

Up to 95% of kids with recurring stomachaches are diagnosed by pediatric gastroenterologists as functional abdominal pain, Dr. Ziring says.

Functional abdominal pain is a condition that, following examination and evaluation, can't be explained by physical abnormalities in your child's body. Irritable bowel syndrome (IBS) is classified as a type of functional abdominal pain when it includes a change in bowel habits, chronic constipation or diarrhea.

"Children with functional abdominal pain are acutely sensitive to the sensations their bodies are giving them," Dr. Ziring says.

"It's a mind-body problem of communication between the brain and the gut that causes abnormal perceptions and heightened response to pain. Their brains amplify signals as being exquisitely painful when other people might not even recognize them."

Dr. Ziring cautions parents against looking for answers or solutions in consumer tests that claim to detect food allergies, leaky gut or disturbances to the microbiome.

"Often these tests raise more concerns for parents, in addition to legitimate concerns about their child's pain," he says. "Food allergies are not a significant contributor to isolated abdominal pain in children, and it's difficult to take that information and come up with medical treatment."

Read: Tummy Trouble Tips

Functional abdominal pain can be diagnosed without testing—but physicians can perform a simple battery of blood and stool tests to look for conditions such as an overgrowth of intestinal bacteria, the presence of stomach ulcers, celiac disease and IBD.

"A diagnosis can be a relief for parents, but it can be frustrating as well when you can't point to lab tests to indicate a problem," Dr. Ziring says. "But it's common to have abdominal pain. There are treatments, and it almost always gets better."

Functional abdominal pain is not caused by sadness, stress or anxiety, but those feelings and emotions can worsen a child's pain. Mind-body solutions such as sports, music and other highly engaging, pleasurable and distracting activities can help—as can medications for abdominal spasms and changes to diet.

Your child's physician can help tailor solutions specifically based on your child's symptoms and your family's circumstances.