In approaching abdominal pain, the first question that we have to answer is where’s the pain coming from. It turns out this is not a very easy question to answer. Just because a patient points at his or her stomach, does not mean that the pain is necessarily coming from this organ.
There are two additional possibilities to consider. It turns out many patients experience chronic abdominal pain from what we call “abdominal wall“–the skin, muscle, fat that surrounds the abdominal organs.
The reason why this distinction is important is because treatment for pain coming from the organs–so-called “visceral pain“–is quite different from that for pain coming from the abdominal wall–so-called “somatic pain“. The abdominal and pelvic organs are served by visceral nerves. On the other hand, the abdominal wall is served by somatic nerves.
To treat the visceral pain coming from, for example, the intestine or the stomach, we target the visceral nerves. To treat somatic pain coming from the abdominal wall, we target the intercostal nerves or their branches.
Finally, an important source of abdominal pain is “referred pain“. This is the phenomenon where the brain perceives pain as coming from a place where it is not. The classic example is where people who have heart attacks may experience left arm pain. For the abdomen, some patients have referred pain coming from the back–the paraspinal muscles–or from the side, the serratus anterior.
Pain physician & PhD computational biologist @StanfordPain • Advanced pain interventions with CIPS & FIPP • Opinions mine & not medical advice