Creve U, Hubens A
Dis Colon Rectum. 1979 Oct;22(7):483-5. doi: 10.1007/BF02586937.
In this study, the authors recorded pre- and postoperative anal resting pressures in 28 patients with hemorrhoidal disease and in 32 controls. No significant difference was found between these two groups preoperatively. In the patient population anal pressure was significantly lowered following Lord's anal dilation treatment. No such pressure reduction was recorded after a standard St. Mark's hemorrhoidectomy. Finally, the authors confirm that anal pressure measurements record only the tonus of the sphincter apparatus and are not influenced by the volume of the hemorrhoidal masses themselves.