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Videodefecography: a study of the rectal motile pattern.
A Shafik1, A A Shafik, O El-Sibai
1Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo, Egypt. shafik@ahmed-shafik.org
Surgical and Radiologic Anatomy : SRA
|June 5, 2003
Summary
Rectal motility occurs in a "mass squeeze" pattern, initiated at the rectosigmoid junction (RSJ) during evacuation. This study used videodefecography to observe rectal contraction waves, differentiating between complete and incomplete evacuation events.
Area of Science:
- Gastroenterology
- Physiology
Background:
- The precise mechanism of rectal motility, crucial for defecation, has been poorly understood.
- Previous research suggested electromechanical activity indicated a "mass squeeze" pattern.
Purpose of the Study:
- To investigate rectal motility patterns during evacuation using videodefecography.
- To characterize the dynamics of rectal contraction waves and their role in defecation.
Main Methods:
- Videodefecography was employed to record evacuation dynamics in 28 healthy volunteers.
- Rectal electromechanical activity was analyzed during voluntary defecation attempts.
Main Results:
- Rectal motility at rest showed no peristalsis or segmentation.
- Upon attempted evacuation, a contraction wave initiated at the rectosigmoid junction (RSJ) spread aborally, causing anal canal opening and RSJ closure.
- Two types of waves were observed: complete (evacuating) and incomplete (non-evacuating). Physiologic rectal intussusception or rectocele occurred in a few subjects.
Conclusions:
- Rectal motility functions as a "mass squeeze" mechanism, coordinated by waves originating at the RSJ.
- Videodefecography provides detailed insights into the mechanics of rectal evacuation and associated phenomena.