Visceral Hypersensitivity: A Major Source of Abdominal Pain
If you have ever been sunburned, then you have experienced hypersensitivity. Your skin was very sensitive to light touch, warm water and clothing for days. Well, imagine if that sensitivity was being experienced in your gut. Some people are troubled by such a problem called visceral hypersensitivity.
The phenomenon of hypersensitivity involves the nervous system. At some point, the irritation to a particular organ system like the skin or the gut leads to the sensitization of the nervous system, the alarm system. In severe cases, the central nervous system becomes so hypersensitive that everything seems to hurt. Painful stimuli become even more painful; that sensitivity is called hyperalgesia. Even non-painful stimuli like touch become painful; this sensitivity is called allodynia. In the case of visceral hypersensitivity, everything from digestion to urination can become painful. Thus, many conditions are linked to visceral hypersensitivity like: noncardiac chest pain, nonulcer stomach pain, irritable bowel syndrome, and severe menstrual cramps.1 All of these conditions are really just a form of visceral hypersensitivity. And many people are affected by one form of it or another.
For one reason or another, irritation to the internal organs early in life2 or chronic irritation for many years can lead to visceral hyperalgesia. This matter is not just about physical insults or inflammation. This matter can also be caused by anxiety and stress. But all roads eventually lead to the central nervous system, the brain.
Women seem to be the most commonly affected group of people. But the diagnosis of visceral hypersensitivity can be difficult because gut pain can be so vague, so hard to pinpoint and so widespread. The biggest hallmark of visceral hypersensitivity to watch out for is pain provoked with normally non-painful stimuli. Some people might experience pain right after ingesting food or water or while the bolus of food or water moves through the intestinal tract. Others have pain when the bladder is full or when it is time to have a bowel movement. Pain during normally non-painful body functions is a clue that the abdominal organs might be hypersensitive.
Once the diagnosis of visceral hypersensitivity is made, the treatment can be tricky. At first, medications used to prevent overstimulation can be used like proton pump inhibitors that reduce stomach acid production or spasmolytics that reduce gut motility. A secondary approach might introduce medications used to treat nerve pain like the anti-convulsants (that can calm the nervous system) or the tricyclic analgesics (that can also reduce nervous system sensitivity). Of course, there is an option to use opioids, but that can also lead to long term consequences like opioid-induced hyperalgesia and more pain. Alternatives to medications are also worth mentioning for the treatment of visceral hypersensitivity, especially those that provoke a relaxation response like meditation, hypnosis or visualization. Like most forms of nervous system sensitization that cause pain, a multi-dimensional approach is more likely to work than a singular approach to this very difficult problem.
For many people who experience this type of abdominal pain, it is difficult to switch the focus away from the gut and to the brain. But for centuries, people have long understood that there is a very strong connection between the gut and the brain. Visceral hypersensitivity entangles both the internal organs and the central nervous system in a nasty web of chronic pain. In order to untangle that web, the source of pain needs to be treated all the way to the brain.
Gut. 2006 July; 55(7): 905-908.
Journal of Pediatric Gastroenterology & Nutrition: October 2005 - Volume 41 - Issue 4 - p 554