Pelvic floor study in patients with obstructive defecation: influence of biofeedback

The aim of this study was to evaluate the pathophysiologic abnormalities in patients with obstructive defecation or dyssynergia and to assess the role of biofeedback treatment. Three groups were studied. Group A had 24 patients with obstructive defecation; B, 25 patients with constipation; and C, 22 healthy volunteers. Rectosigmoid segmental transit time of group A was 28.5 hours (SD +/- 13.4); B, 17.2 hours (SD +/- 11.5); and C, 8.5 hours (SD +/- 6.3) (p < 0.05). There was no statistical difference in resting and squeezing anal pressure among the three groups. Anorectal angle at rest revealed no difference among the three groups. At strain, a statistically significant difference between groups A and C (p < 0.05) and a marginal difference between groups A and B was noted. Rectocele of the anterior rectal wall was present at strain in 17/24 patients of group A and 7/22 patients of group C (p < 0.05). Electromyography during strain revealed abnormal contractions of puborectalis muscle and external anal sphincter, in 13 and 14 patients of group A, respectively, which differed from that observed in groups B and C (p < 0.001). Biofeedback treatment was applied with good results in 7 of 11 patients of group A. At six months, constipation relapsed in only one of treated patients. Patients suffering from obstructive defecation seem to have slower rectosigmoid transit time than the others. Defecography shows smaller anorectal angle at strain and rectocele of the anterior rectal wall more often. Abnormal pelvic floor contraction at strain is often noted in anal electromyography. Some of these patients seem to respond favorably to biofeedback treatment.