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Irritable Bowel Syndrome (IBS) Health Center

What Is Irritable Bowel Syndrome (IBS)?

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The mornings with irritable bowel syndrome are the most challenging for Jeffrey Roberts. His stomach cramps up. He feels like he needs to be near a bathroom at all times. So he gives himself at least 2 hours to get ready for work. When he goes out, he often takes routes he knows will have public restrooms along the way.

This is reality for Roberts and up to 20% of American adults who suffer from irritable bowel syndrome (IBS) at some point in their lives. Their exact symptoms, and the severity, may differ. But for people with IBS, daily life is greatly influenced by the way their digestive system behaves. A flare-up of symptoms can mean hours of misery.

"IBS is an illness which seems to strike people down," says Roberts, president of the IBS Self Help and Support Group.

What causes these recurring symptoms of abdominal pain, bloating, gas, diarrhea, or constipation?

Doctors don't have a clear picture what IBS is or what causes it. But researchers do have a few theories:

  • IBS sufferers may have a more sensitive colon than others.
  • In people with IBS, the brain may perceive contractions in the gut more acutely than others.
  • The immune system may respond differently to stress and infection in people with IBS.
  • Hormonal changes may trigger IBS symptoms (70% of those who suffer from IBS are women).
  • The neurotransmitter serotonin that is produced in the gut may act on digestive tract nerves. Those with diarrhea may have increased serotonin levels in the gut, while those with constipation-predominant IBS have decreased amounts.

Though no one fully understands what causes IBS, doctors do agree that IBS is a bona fide medical condition. They do not think it's "all in your head." According to the American College of Gastroenterology, IBS is also clearly defined by what it is not:

  • It is not an anatomical or a structural problem.
  • It is not an identifiable physical or chemical disorder.
  • It is not a cancer and will not cause cancer.
  • It will not cause other gastrointestinal diseases.

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