Defecography in patients with anorectal disorders. Which findings are clinically relevant?

To evaluate the results and clinical impact of defecography in patients with anorectal disorders, 100 results of defecographic examinations from 92 patients were reviewed. The defecographic results were screened for the anorectal angle, defined both at rest and during straining, perineal descent, and abnormalities of the rectal configuration during straining. Anal manometry, saline infusion test, rectal capacity measurement, and anal electromyography (EMG) were also performed. There was a significant difference (P less than 0.001) both at rest (22 degrees) and during straining (12 degrees) between the two anorectal angle measurements. Incontinent patients had a larger anorectal angle, both at rest and during straining, than continent patients (P less than 0.04), but with a large overlap. The anorectal angle was not influenced by gender or age. An abnormal rectal configuration was found in 62 defecographic examinations. From the 8 patients with rectopexy performed for a large rectocele or intussusception, incontinent patients with an intussusception had the best results. In four patients, anal EMG showed an increased activity of the external sphincter during straining. Two of these four patients had abnormal defecograhic results. No correlations were found between anorectal angle and the other function tests. In conclusion, the anorectal angle lacks clinical relevance. In patients with defecation problems, defecography may be indicated whenever other investigations (physical examination, anal manometry, anal EMG) have excluded local pathology or a spastic pelvic floor syndrome. In these situations, defecography could detect an intussusception, which could easily be treated with rectopexy.