What Is Irritable Bowel Syndrome?

Irritable bowel syndrome (IBS) is a common intestinal disorder that affects the colon (the large intestine). The colon's main job is to absorb water and nutrients from partially digested food. Anything that is not absorbed is slowly moved through the colon toward the rectum and out of the body as waste in the form of feces (poop).

Muscles in the colon work to get rid of the body's waste products. They contract and relax as they push the undigested food through the large intestine. These muscles also work with other muscles to push the waste out of the anus.

If the muscles in the colon don't work at the right speed for proper digestion or if the coordination with muscles in the rectum or pelvis is interrupted, the contents of the colon can't move along smoothly. When this happens, a person can feel the belly cramps, bloating, constipation, and diarrhea that may be signs of IBS.

Who Gets Irritable Bowel Syndrome?

A lot of teens have IBS. It's estimated that between 6% and 14% of all teens have IBS symptoms. It seems to affect more girls than guys.

The good news is that although IBS can be uncomfortable, embarrassing, and even painful, it's not life threatening. And, unlike other digestive conditions, such as inflammatory bowel disease, IBS doesn't carry a risk of permanent damage to the intestines.

What Are the Signs & Symptoms of IBS?

The symptoms of IBS are usually recurring. This means that a person will have bouts of symptoms on an ongoing basis rather than just once or twice a year. People with IBS often notice their symptoms flare up at certain times. For some people, it's whenever they eat a large meal. For others, it's when they're under a lot of pressure or stress. Some girls notice that they get IBS symptoms around the time of their periods.

The main symptom of IBS is belly pain or discomfort (bloating, etc.). Of course, having a stomachache, gas, or bloating once in a while doesn't mean a person has IBS.

People with IBS have at least two of these symptoms:

  • pain or discomfort that is relieved when they go to the bathroom and have a bowel movement
  • pain or discomfort along with changes in their regular bowel movement patterns (for example, going to the bathroom a lot more or a lot less than usual)
  • pain or discomfort along with changes in the way the stool (poop) looks. Some people become constipated and their stools get hard and difficult to pass; other people get diarrhea.

Because IBS is a problem with the colon, and the colon removes water from unprocessed food waste, it's common for people with IBS to be constipated or have diarrhea:

  • Constipation happens when waste matter remains in the colon for too long so that too much water is absorbed. This makes the stool hard and difficult to pass.
  • If the muscles in the colon move the contents along too fast, though, the colon doesn't have a chance to remove enough fluid, so the person gets diarrhea.

What Causes Irritable Bowel Syndrome?

No one knows exactly what causes IBS, although it tends to run in families.

A prior infectious illness (such as gastroenteritis) may increase a person's risk for IBS. Exposure to a bacterial or viral infection can cause inflammation that can change how the gastrointestinal system works.

Stress can also play a part in IBS. Stress can accelerate your colon and slow your stomach.

Foods can also be a trigger, but this is hard to predict. For example, a high-fat diet may bother some people, but not others. Eating big meals and spicy foods often cause problems, as do drinks with caffeine (coffee or soda), alcohol, milk and milk products, and grains like wheat, barley, or rye. Some of these foods are linked to other digestive conditions like lactose intolerance or celiac disease, though, so it's important to see a doctor if you think a food is causing digestive problems.

Some medicines, like antibiotics , can trigger IBS symptoms in people who have the disorder.

How Is Irritable Bowel Syndrome Diagnosed?

There is no specific test to diagnose IBS. Doctors usually diagnose it based on a physical exam and a patient's symptoms. For example, if someone has had belly pain for more than 12 weeks out of the previous year (not necessarily 12 weeks in a row), it's a sign to a doctor that IBS may be a possibility.

A doctor will probably ask how often you have stomach or gas pain, whether you're ever constipated or have diarrhea, and if so, how long these problems last. He or she may ask questions about your bathroom habits, such as whether your bowel movements are regular, what your stools look like, and whether you ever feel like you need to have a bowel movement but then can't.

It may feel embarrassing or even silly to answer these questions, but learning as much as possible about your symptoms will help the doctor diagnose what's going on.

Besides doing an exam, the doctor will ask you about any concerns and symptoms you have, your past health, your family's health, any medicines you're taking, any allergies you may have, and other issues. This is called the medical history . You may need to ask a parent or other adult for some information.

Although there's no test for IBS, a doctor may send a patient for tests to make sure the symptoms aren't being caused by other problems.

How Is Irritable Bowel Syndrome Treated?

There's no cure for IBS. But there are ways to take control of IBS symptoms. Here are some of the things that doctors recommend:

  • Diet changes. Some people with IBS find that careful eating helps ease or stop IBS symptoms. You might try avoiding very large meals, drinks with caffeine, spicy or fatty foods, chocolate, some dairy products, and foods that contain gluten. Some people find that adding fiber — eating more fruits and vegetables, for instance — and drinking more water can help stop IBS symptoms, too.

    Also try eating regular meals, avoiding on-the-run eating, and paying attention to good nutrition.
  • Lifestyle changes. If you have IBS that appears related to stress, you might want to make some changes. Consider ways to manage daily pressures, such as schoolwork, and make time for activities you enjoy.

    Be sure to get enough sleep and exercise. Your doctor might recommend some stress-reduction techniques, like breathing exercises. Research also shows that hypnotherapy may help in managing IBS.
  • Medicines. For some people with severe IBS, doctors may suggest one of several prescription or over-the-counter medicines. Depending on the symptoms, doctors may recommend over-the-counter laxatives (for constipation) or anti-diarrhea medicines, or might prescribe muscle relaxers (for colon muscle spasm) or antidepressants (for anxiety and stress). Before trying any over-the-counter medicines, talk to your doctor first to be sure you get the best one for you.

Your doctor will have suggestions on what might work for you. You also can keep a food diary so you can see if some foods and events seem to trigger your IBS symptoms. Record what you eat, what symptoms you have, and when they happen.

What's Life Like for Teens With Irritable Bowel Syndrome?

If you're living with IBS, you may worry about anything that could trigger symptoms — even otherwise fun events like playing in a championship game or going out for a fancy dinner before the prom.

Learning more about IBS and what triggers your symptoms is the first step to taking action. Then, do what you need to take care of yourself, whether that's reducing stress by talking over problems with a school counselor or therapist, or watching out for spicy food.

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Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.