A person with irritable bowel syndrome (IBS) has a digestive system that does not function properly, even though nothing appears to be medically wrong. A "syndrome" is a collection of symptoms. Those aren't difficult to describe for IBS: abdominal pain or discomfort, excess gas, bloating and distension, and diarrhea or constipation (or both). But what causes them?
Although IBS research is one of the most active areas in medicine today, we still do not fully understand why people have it. There are probably multiple, interwoven strands of causation, with the gut microbiome at the core. People with IBS have a less diverse community of microbes living in their gastrointestinal tracts, and those microbes produce different types and amounts of gas compared to those residing in people without IBS. In some cases, overgrowth of bacteria in the small intestine (SIBO) may occur. Abnormal motility (gut muscle function) may be a problem for some people with IBS. It can be triggered by too much (or certain types) of gas or fluid in the gut. People with IBS may experience more pain than other people do from sensations that occur when excess gas or fluid build up in the large or small intestine; we call this visceral hypersensitivity. Neurotransmitters such as serotonin, which also regulate mood and response to stress, are certainly involved. Immune activation and inflammation are emerging as IBS triggers, as well. As these medical mysteries are solved and specific causes of gastrointestinal symptoms are recognized, the diagnosis of IBS might be made less often. But for now, it remains the 6th most common diagnosis in primary care, and a leading cause of referrals to gastroenterology specialists.
If you have IBS, you are not alone. Up to 15% of adults have irritable bowel syndrome; that's over 45 million people in the U.S. alone. Though few of us discuss it with others due to its "indelicate" nature, it is actually the second leading cause of work absenteeism.
For some people, IBS is merely a nuisance. For others, it can be disabling, especially if accompanied by depression and fatigue. At its worst, IBS can take over a person's life, jeopardizing relationships, jobs and quality of life. It's expensive, too. In addition to lost time at work, people with IBS spend lots of money on doctor's appointments, tests and procedures, emergency department visits, and medications.
Given how complicated IBS can be, would it shock you to learn that you might be able to manage your IBS symptoms by simply making different food choices? It's true: the FODMAP-elimination diet is a game changer! Do you have IBS because you've been eating the wrong diet? Not likely. However, finding the diet that's right for you can help you enjoy food again and put you in control of your bathroom habits. Until scientists learn more about the root causes of IBS, that's important.