# Repetitive rectal painful distention induces rectal hypersensitivity in patients with



## Kathleen M. (Nov 16, 1999)

J Gastroenterol. 2006 Mar;41(3):217-22. Related Articles, Links Repetitive rectal painful distention induces rectal hypersensitivity in patients with irritable bowel syndrome.Nozu T, Kudaira M, Kitamori S, Uehara A.Department of Comprehensive Medicine, Hokkaido University Hospital, Kita 14, Nishi 5, Kita-ku, Sapporo, 060-8648, Japan.BACKGROUND: A reduced rectal perceptual threshold has been reported in patients with irritable bowel syndrome (IBS), but this phenomenon may be induced by a comorbid psychological state. We evaluated the rectal pain threshold at baseline and after conditioning (repetitive rectal painful distention: RRD) in patients with IBS or functional abdominal pain syndrome (FAPS), which is an abdominal pain disorder, and in healthy controls, and determined whether rectal hypersensitivity is a reliable marker for IBS. METHODS: The rectal sensory threshold was assessed by a barostat. First, a ramp distention of 40 ml/min was induced, and the threshold of pain and the maximum tolerable pressure (mmHg) were measured. Next, RRD (phasic distentions of 60-s duration separated by 30-s intervals) was given with a tracking method until the subjects had complained of pain six times. Finally, ramp distention was induced again, and the same parameters were measured. The normal value was defined by calculating the 95% confidence intervals of controls. RESULTS: Five or six of the seven IBS patients showed a reduced rectal pain threshold or maximum tolerable pressure, respectively, at baseline. In all patients with IBS, both thresholds were reduced after RRD load, but they were reduced in none of the patients with FAPS. RRD significantly reduced both thresholds in the IBS group (P < 0.05), but it had no effect in the control or FAPS groups. CONCLUSIONS: Rectal hypersensitivity induced by RRD may be a reliable marker for IBS. Conditioning-induced visceral hypersensitivity may play a pathophysiologic role in IBS.


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## SteveE (Jan 7, 1999)

This is interesting on two levels. First of all, what IBSer would consent to induced pain?!







Secondly, I understand the results, but I'm confused by the conclusion. As I understand it, IBSers, but not controls had a reduced pain threshold after they induced the distention. Why does that mean conditioning may play a role? Isn't it equally likely that something biological is screwed-up? Either way, does this mean that the more we have pain, the more we're going to sense smaller units of pain? And how long does that effect last?Based on my own experience, after an intial flare-up of symptoms, it does seem like every little gas bubble that didn't cause me pain before the flare-up does for at least a week. Interesting...


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## Kathleen M. (Nov 16, 1999)

Yep I think there is a the more there is pain the less it takes to get pain the next time thing going on. I'd have to read the whole article before I had a good feeling for all the nuances (abstracts often are written so tersely it can be hard to deconstruct what they are really saying







)Why anyone would submit to this? for me I did a test like this as it was part of a clinical trial where I might get effective treatment. They do have small trials like this where that isn't part of a bigger study, and usually people do things like this because they think it may help them and others once the doctors understand better what is going on.Rectal hypersensitivity seems like something that they might eventually be used as a positive diagnosis for IBS, so they do need to understand it. It would be nice if something like this didn't happen in people with other GI isses but just the functional bowel group, I think many patients would feel better if they could have something that pointed to yes it is IBS rather than just the nope it isn't anything else.What is causing the rectal hypersensitivity can still be biological even with these results, I'm not sure the whole conditioning thing means it is not a physiological response (that it something in this in anyway proves it is all in our head or anything)I did this sort of test before and after the treatment in the clinical trial and I did find it was much easier to deal with when the IBS was a lot better, so personally, I think it can be used as a marker for IBS for a lot of people.K.


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