Repetitive rectal painful distention induces rectal hypersensitivity in patients with irritable bowel syndrome

Abstract

Rectal hypersensitivity induced by RRD may be a reliable marker for IBS. Conditioning-induced visceral hypersensitivity may play a pathophysiologic role in IBS.

Corticotropin-releasing factor induces rectal hypersensitivity after repetitive painful rectal distention in healthy humans

“…18 Since RRD in the present study is also a visceral stimulation, RRD may stimulate CRF release. On the other hand, the present study also revealed that RRD without iv-CRF did not alter rectal sensation, which is consistent with our previous report, 7 and, moreover, iv-CRF alone did not induce it either, suggesting that both exogenous (iv) and endogenously released CRF in the brain induced by RRD may be required to achieve rectal hypersensitivity. Because of the bloodbrain barrier, iv-CRF does not penetrate to the brain.…”

“…7 In our present study, we also showed that PT in the basal state was 32-35 mmHg (n = 21, all men), and recently another preliminary Japanese study reported that PT of healthy male subjects (n = 6) is around 32 mmHg. 15 Since these values are quite comparable, the reproducibility of PT between different Japanese subjects and laboratories seems to be quite good, indicating that these values can be considered reliable.…”

“…These protocols were previously reported to successfully induce rectal hypersensitivity in IBS patients, but not in healthy controls or patients with functional abdominal pain syndrome. 7 The second experimental series was performed to determine the effects of CRF without RRD on rectal sensation. Subjects were first given ramp distention to determine PT.…”

“…4 Moreover, we recently demonstrated that repetitive painful rectal distention (RRD) induces rectal hypersensitivity in IBS patients, and this response is not observed in either healthy controls or in patients with functional abdominal pain syndrome, another FGID in which patients complain of chronic abdominal pain without organic diseases, similar to IBS. 7 Since visceral stimulation can be interpreted as stress in IBS, 2 these lines of evidence suggest that stress-induced altered visceral sensation may be a specific visceral response to this disorder.…”

Irritable bowel syndrome - from etiopathogenesis to therapy

“…This selective hypersensitization occurs as a result of stimulation of various receptors of visceral afferent nerve fibres in the gut wall, triggered by bowel distention or bloating, and is a possible explanation for IBS symptoms. The increased sensitivity of the colon could be influenced by a psychological tendency to report pain and urgency, rather than increased neurosensory sensitivity 26,27 .…”