Investigation of anorectal function.

Anorectal function tests were performed in 280 consecutive patients, who were referred for evaluation of different anorectal disorders. The relationship between the estimated anal sphincter pressure on digital palpation and the measured pressure on anal manometry was investigated and the interrelationship between anal manometry, rectal capacity and the saline infusion test was defined. A significant correlation (P less than 0.001) was found between digitally and manometrically measured anal sphincter pressure. Considering the relationship between the three specific anorectal function tests, only manometry and the saline infusion test correlated to some extent (P less than 0.01). This study shows that digital palpation is helpful in anorectal function investigation, but to establish the exact anal pressures, anal manometry is mandatory. Furthermore, the poor correlation observed indicates that single tests represent different aspects of anorectal function and therefore they need to be performed together.