| Abstract: | Anal ultra slow waves (USWs) have been describedin a variety of anorectal disorders, all of which may beassociated with constipation. We investigated whetherthey represent a marker for dyschezia and whether their occurrence can be modified.Manometric and endosonographic studies were performed in25 patients with dyschezia, in 25 age- and sex-matchedcontrols, and in an equal number of patients with hemorrhoids. Patients exhibiting ultra slowwaves were repeatedly studied with and without localadministration of isosorbide dinitrate. In addition, wedetermined whether stimulatory maneuvers modify the occurrence of USWs. Anal USWs were persistentlyfound in 56% of patients with dyschezia, in 8% ofpatients with hemorrhoids, and in none of the healthycontrols. They were stimulated by anal squeeze and completely abolished by local administration ofisosorbide dinitrate. Ultra slow waves always occurredin conjunction with an increase in anal resting pressureand were tightly associated with a fluctuation in slow wave amplitude. Anal sphinctermorphology was similar in patients with dyschezia and incontrols. We conclude that anal USWs occur mostfrequently in patients with dyschezia and indicatesmooth muscle dysfunction. Treatment directed atabolishing this motor phenomenon may represent a novelapproach to the management of patients withdyschezia. |
