About 11% of people struggle with IBS (irritable bowel syndrome). The symptoms are usually abdominal pain combined with diarrhea, constipation or both.

The weird thing about IBS is that there's no sign of damage to the intestines. Still, the symptoms can be brutal and it can certainly have a negative impact on overall quality of life.

So, what causes IBS? Researchers have been trying to figure it out for years and it looks like they've found the answer.

In 1990, researchers found something interesting. Using a balloon inserted into participants' intestines, they found that IBS patients experienced pain at much lower pressure levels compared to healthy individuals.

While only 6% of the control group felt pain at 60 milliliters of balloon inflation, 55% of IBS patients reported pain at the same level.

They also found that people with IBS were nearly ten times more likely to experience pain at a given level of pressure. (Source)

Remember - if the intestines showed any sign of damage, this would all make sense, but the intestines of the IBS patients look healthy and undamaged. So why do they experience more pain than the control group?

This phenomenon, called visceral hypersensitivity, is very common in people with IBS. People with visceral hypersensitivity are simply more sensitive to pressure inside the gut than others.

Since people with IBS experience more pain even though the actual stimuli on the gut is completely normal and there's no sign of damage to the intestines, it means the problem is in the communication between the gut and the brain - also called the gut-brain axis.

In another study, researchers looked at PET scans of the brains of people with IBS and a control group. A PET scan looks at blood flow in the brain to see which areas are activated.

When experiencing or anticipating rectal distension (movement and pressure in the lower part of the intestines), people with IBS showed activation of the prefrontal cortex. (Source)

The prefrontal cortex is involved in accessing and regulating emotional memories. You can say the prefrontal cortex interprets the present situation with past experiences in mind. It can do this by recalling experiences possibly going as far back as the baby stage of life.

When the people with IBS show activation in this part of the brain related to their bowel movements, it suggests that emotional processes are happening.

Now we know that IBS patients have higher sensitivity to pain because of a disturbance in the brain-gut axis. We also know that there are emotional processes triggered by activity in the gut.

Unfortunately, another connection was made when researchers realized that there are high rates of physical and emotional abuse among IBS patients (Source).

One study revealed that 66% of female IBS patients had experienced physical or sexual abuse. (Source)

When exposed to physical or emotional trauma, the nervous system can become more sensitive to both stress and physical sensation. This hypersensitivity causes the body to struggle with interpreting internal signals, leading to a state where normal bodily processes like digestion can trigger pain responses.

Normal signals from food, liquids, and gas are perceived as painful, even though there's no actual physical damage to the intestines.

This means that IBS might result from a dysregulated nervous system.

To be perfectly clear, this doesn't mean all people who suffer from IBS has experienced abuse.

While nervous system dysregulation from trauma is not the only potential cause, the evidence we have discussed here reveals that IBS is more than just a physical condition - it's a complex interaction between emotions and bodily responses.

The good news is that this understanding opens new paths for research, treatment and support.

Thanks for reading! This newsletter was inspired by the book When The Body Says No by Dr. Gabor Maté.

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