ABSTRACT
The etiology of IBS is not completely understood. However, IBS has been associated consistently with visceral hypersensitivity. Balloon distention studies have shown that patients with IBS feel discomfort at a lower volume than do subjects without IBS. Patients with IBS and subjects without IBS do equally well on tests of somatic pain such as cold water immersion, a suggestion that IBS is a disorder specific to the gut. Balloon distention studies also have suggested that patients with IBS have hypersensitivity throughout the gastrointestinal tract. The frequent overlap between IBS and fibromyalgia and urinary symptoms suggests that the problem may be an even more diffuse visceral hypersensitivity.
