Changes in tolerance to rectal distension correlate with changes in psychological state in patients with severe irritable bowel syndrome.
OBJECTIVE
Reduced tolerance to rectal distension has been regarded as a biological marker for irritable bowel syndrome (IBS), but longitudinal studies are few. This study determined whether change in tolerance to rectal distension after psychological treatments was associated with: 1) change in abdominal pain; 2) change in psychological symptoms; 3) a reported history of sexual abuse.


METHODS
Participants completed a visual analogue scale of abdominal pain, SCL-90 and Hamilton rating scale of depression; discomfort threshold to rectal distension was determined using a double random staircase protocol. These were measured at entry to a trial of psychotherapy or paroxetine (selective serotonin reuptake inhibitor antidepressant) and 3 months later (N = 52). Analysis of change scores were adjusted for treatment group and baseline values.


RESULTS
Increased tolerance to distension after treatment was associated with reduction in depression (r = -0.37, p =.008) but not abdominal pain. Patients who reported prior sexual abuse showed greater increase in tolerance than the remainder (changes in volume threshold: -24.7 ml [SEM = 12.1] vs. 3.6 ml [SEM = 6.2], adjusted p =.045; changes in pressure threshold: -4.7 [SEM = 1.7] mm Hg vs. 0.96 [SEM=0.9], adjusted p =.005). Multiple regression indicated that reduction in depression score and a reported history of sexual abuse were independently associated with improved tolerance to distension.


CONCLUSIONS
In patients with severe IBS, increased tolerance to rectal distension after psychological treatment is significantly associated with improved depression and reported sexual abuse. These results suggest that in some patients with severe IBS psychological rather than biological processes are primarily responsible for reduced tolerance to rectal distension.
Guthrie
Elspeth
E
School of Psychiatry and Behavioural Science, University of Manchester, Manchester, UK.
Barlow
Jo
J
Fernandes
Lakshmi
L
Ratcliffe
Joy
J
Read
Nicholas
N
Thompson
David G
DG
Tomenson
Barbara
B
Creed
Francis
F
D015746:Abdominal Pain / Q000175:diagnosis / Q000523:psychology; D000328:Adult; D015415:Biomarkers; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology; D004106:Dilatation / Q000523:psychology; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology; D017374:Paroxetine / Q000627:therapeutic use; D011569:Psychiatric Status Rating Scales; D011613:Psychotherapy; D012007:Rectum / Q000502:physiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use
D015415:Biomarkers; D017374:Paroxetine; D017367:Selective Serotonin Reuptake Inhibitors