What Is Visceral Hypersensitivity?

woman holding her stomach in pain
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Visceral hypersensitivity (visceral hyperalgesia) is the term used to describe the experience of pain within the inner organs (viscera) at a level that is more intense than normal. In other words, a person who experiences visceral hypersensitivity will have a lowered threshold for abdominal pain and discomfort in response to pressure, stimulation, or distension within the abdomen.

Visceral hypersensitivity is a hallmark characteristic of irritable bowel syndrome (IBS).

However visceral hypersensitivity may also be present in people who have:

Measuring Visceral Hypersensitivity

The predominant research area regarding visceral hypersensitivity is as a means of understanding why people have IBS. For research purposes, visceral hypersensitivity is commonly measured using a balloon distension test. This tests the response of the patient to pressure within the rectum.

In the balloon distension procedure, a balloon into the rectum and slowly filled with air. Individuals are characterized as having visceral hypersensitivity when they report pain at lower levels of pressure than others who are able to withstand more significant air inflation without reporting discomfort. In such research studies, people who have IBS typically experience a lower pain threshold.

Visceral Hypersensitivity and IBS

Although visceral hypersensitivity is seen as so integral to IBS, only approximately 30 to 40% of people who have IBS have been found to have an exaggerated sensitivity to distension within the colon.

And, interestingly, there is not necessarily a direct correlation between this enhanced sensitivity and the severity of a person's IBS symptoms.

Causes of Visceral Hypersensitivity

Once visceral hypersensitivity was established as a key component in IBS, researchers have turned their attention as to why that might be as a way to better understand the confusing nature of IBS.

There are various theories behind the experience of visceral hypersensitivity in IBS. Many factors are being investigated, including:

A better understanding as to how these complex systems all interact will allow for the development of medications that will target the areas of dysfunction and bring about relief from IBS symptoms.

Sources:

Akbar, A., Walters, J., & Ghosh, S. "Visceral hypersensitivity in irritable bowel syndrome: molecular mechanisms and therapeutic agents" Alimentary Pharmacology & Therapeutics 2009 30:423-435.

Zhou, C. & Verne, N. "New insights into visceral hypersensitivity — clinical implications in IBS" Nature Reviews Gastroenterology & Hepatology 2011 8:349–355.

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