Reasons Why IBS Is Not All in Your Head

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One of the most frustrating things about suffering from irritable bowel syndrome (IBS) is the lack of physical proof of the cause of the disorder, making it seem as if it is "all in your head". While struggling with debilitating symptoms and after undergoing a variety of tests, patients are often told “There is nothing wrong” or “It's just stress.” In fact, IBS is classified as a functional gastrointestinal disorder because no visible inflammation or tissue abnormality can be seen through routine diagnostic testing. However, this does not necessarily mean that there is nothing physically wrong with a person who suffers from IBS. Researchers are pursuing five areas in which there may be a difference between the bodies of people who suffer from IBS and those who don’t.


Motility refers to the movement of the smooth muscle of the digestive tract. Although research has not shown consistent results, there is some evidence that the speed of this movement is altered in both the colon and the small intestines of individuals with IBS. Contractions that are faster than usual are seen in some individuals who suffer from diarrhea-predominant IBS (IBS-D), whereas the muscle movements are too slow in some individuals who suffer from constipation-predominant IBS (IBS-C).

Visceral Hypersensitivity

Visceral hypersensitivity is a heightened sense of pain in the internal organs of the body. Studies have shown that many patients with IBS experience pain in the rectum at a different threshold level than people who do not have the disorder. It is thought that this difference in pain perception is the result of a process in which the nerves of the gut become over sensitized to stimulation.

Brain-Gut Connection

The digestive system has a sort of brain of its own, the enteric nervous system. This network of nerves directs the processes of digestion and is in close communication with the brain. This interaction is seen most clearly during the stress response. There is evidence that dysfunction in the interactions between the gut and the brain may underlie the motility disturbance and visceral hypersensitivity that result in IBS symptoms. This dysfunction is thought to be related to an imbalance in levels of particular neurotransmitters, which is why IBS sufferers often find relief from symptoms when taking antidepressants that target specific neurotransmitters.


By definition, IBS does not present with visible inflammation. This does not mean that inflammation is not necessarily involved; it just means that the inflammation is not visible during routine diagnostic testing. The evidence is beginning to be seen of the possibility of low-grade chronic inflammation on a cellular level in some individuals who suffer from IBS. This inflammation is thought to most likely be associated with cases in which IBS which was preceded by a bout of gastroenteritis, a condition classified as post-infectious IBS (IBS-PI).

Gut Bacteria

Although not as clear-cut as it sounds, the complicated nature of gut bacteria are most easily understood when classified as good bacteria (such as probiotics), and bad bacteria (those associated with infection and inflammation). Research focus on gut bacteria has begun to offer some evidence that there is a difference between the bacterial makeup of some IBS patients and those who do not suffer from the disorder. Particular attention has been given to the role of bacteria in the small intestine as a contributor to IBS, namely, small intestine bacterial overgrowth (SIBO).

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