The ABC'S of IBS

THE GUT IS A COMPLICATED THE THINGS TPL PLACE, AND SOMETIMES THINGS CAN GET OUT OF SYNC THERE, leading to belly pain, mad dashes to the bathroom, and other symptoms.

- MARISA COHEN

The most common GI disorder is irritable bowel syndrome (IBS), which affects up to 15% of U.S. adults.

The two main symptoms of IBS are pain related to having a bowel movement and changes in the frequency and/or consistency of stool, as in diarrhea, constipation, or both, says Neha Mathur, M.D., a gastroenterologist at Houston Methodist. "If you have one day of diarrhea every two or three months, that is likely food- or environment-related and is not IBS," adds Ashkan Farhadi, M.D., a gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA. "But if you have it over and over at least three times a week and it happens for three months, it might be IBS." Other symptoms may include bloating, gas, and the feeling that you can't quite get everything out when you poop.

The pathology of IBS is still a bit of a mystery, says Dr. Mathur. Unlike inflammatory bowel disease, which is connected to inflammation in the GI tract, IBS doesn't involve inflammation, ulcers, or other visible signs of damage-in the past many people with IBS were told the symptoms were "all in their head." But researchers now believe that many symptoms of IBS may be due to hypersensitivity of the nerves in the wall of the GI tract. "Sometimes the brain-gut signal can get hyperconnected, especially if we're very stressed," Dr. Mathur explains. "That can make those signals work more quickly, causing more abdominal pain and diarrhea. And sometimes the signal is not that great, causing constipation and changes in motility." IBS can also be triggered by a change in the gut microbiome, possibly caused by an infection, use of an antibiotic, or even inflammation elsewhere in the body, Dr. Mathur adds.

THERE ARE THREE BASIC TYPES OF IBS: