The barostat is a device that maintains a constant pressure within an air‐filled polyethylene bag by means of a feedback mechanism. The system measures variations in rectal tone by recording changes in the intrarectal pressure and volume. Different procedures, such as ramp distension or intermittent distension, are used to test visceral sensitivity and rectal wall compliance. It is not quite clear which method is preferable and how the barostat measurements compare with those of the conventional latex balloon. In 28 healthy volunteers (11 males, mean age 36, range 22–67 years) rectal distension was performed in two ways: 1  Pressure‐controlled distension, by both intermittent and ramp methods, with measurement on the Visual Analogue Scale (VAS, 0–5) at 8, 12, 16, 20, 24, 28, 32 and 36 mmHg. Hysteresis (comparing area under the curve during deflation and inflation with ramp pressure distension) and compliance were calculated. 2  Volume‐controlled distension, with registration of first sensation, urge to defecate and maximal tolerated distension. This procedure was compared to conventional water‐filled latex balloon distension. No differences were found between intermittent and ramp distension comparing VAS scores at the same pressures. Gender or age did not affect the VAS score. Males had larger volumes at the same pressures than females. Females had larger hysteresis than males. Older females had larger hysteresis than younger females. The pressure volume curves were S‐shaped. Compliance at maximal tolerated distension (V/p) and maximal dynamic compliance (ΔV/Δp) was higher in males than females. The polyethylene bag had higher MTV and MTP compared to the latex balloon. In conclusion, no differences were found in volumes, compliance or VAS between the intermittent and the ramp pressure‐controlled inflation, indicating potential for simplification of the procedure. Males had larger rectal volumes and compliances; females had more pronounced hysteresis. A systemic difference was found between distension with the water‐filled latex balloon and with the air‐filled polyethylene bag. This should be taken into account when interpreting results.

Background : Prucalopride (PR) is a novel 5‐HT4 agonist enterokinetic compound. Aim : To evaluate its effect on bowel function, gut transit and anorectal function in healthy volunteers using a double‐blind, placebo‐controlled crossover study. Methods : Twenty‐four healthy volunteers (12 men, 12 women, mean age 25 years, range 20–53 years) were randomly assigned to 1 mg/placebo or 2 mg/placebo (PL). The trial consisted of five consecutive 1 week periods: no drug treatment, PR treatment or PL, washout, PL or PR, no treatment. Subjects maintained a diary of bowel function during the entire study period. Total intestinal transit time (TITT), mean colonic transit time (MCTT) and anorectal function (anal manometry, rectal sensitivity and rectal compliance) were assessed at the end of both treatment periods. Electrocardiography and blood sampling were performed for safety analysis; blood sampling was also used to check compliance. Results : No subjects withdrew from the study. Treatment with PR 2 mg showed a statistically significant increase in mean number of weekly stools (11.5 vs. 7.1 compared to PL, P = 0.04) and in the percentage of loose/watery stools (48 vs. 12% compared to PL, P = 0.005). Within 1 week, stool frequency and consistency returned to baseline values when treatment was stopped. MCTT was shortened significantly with both doses, i.e. from 35 h on PL to 25 h on PR 1 mg (P = 0.01) and from 43 h on PL to 22 h on PR 2 mg (P = 0.02). Anorectal function was unaffected by PR. Transient and moderate headache occurred in nine subjects during PR treatment and in six subjects during PL treatment. Conclusion : Prucalopride is well tolerated by healthy subjects and has a marked and consistent effect on stool frequency and consistency, and on colonic transit. In the present study prucalopride did not affect visceral sensitivity or sphincter function. It holds promise for patients with slow transit constipation.

Haemorrhoids are associated with endosono- graphic thickening of submucosal tissue, internal and external anal sphincter. Therefore, both sphincters as well as changes in the submucosa might be of pathophysiological importance. Endosonographic changes cannot predict treatment outcome or symptom recurrence.