Visceral sensitivity in irritable bowel syndrome and healthy volunteers: reproducibility of the rectal barostat.

The reproducibility of rectal visceral sensitivity using the barostat double-random staircase method was evaluated. We tested 15 healthy women and 18 women with irritable bowel syndrome twice. Pressure, volume, and tension were measured at first sensation of gas, stool, and discomfort. There was no significant difference between test and retest. Three different indexes were used as measures of reproducibility. The intraclass correlation coefficients, considered to demonstrate acceptable reproducibility when higher than 0.80, ranged from 0.76 to 0.93 in the healthy volunteers and from 0.53 to 0.88 in the patients. The pooled coefficients of variation ranged from 10 to 24% in the healthy volunteers and from 11 to 49% in the patients. The repeatability coefficients are also given. The results indicate that barostat visceral sensitivity measurements in the rectum may be applicable when comparing groups of subjects.