Purpose: According to the National Institutes of Health, about half of the adult population in the U.S. has hemorrhoids by age 50. Since incidence of hemorrhoids has been found to be very low in the developing world, where people squat for defecation, hemorrhoids have been attributed to the use of the sitting toilet in a few published studies. I undertook this review to find out the available literature on effect of type of posture during defecation and hemorrhoids.
Methods: PubMed (1966-2009) and Embase (1980-2009) databases were searched for publications related to association between type of posture during defecation and hemorrhoids/constipation (since constipation is a well known risk factor for hemorrhoids). I limited the results to studies conducted in humans, age 19 years and published in English. My search yielded 8 published studies on the topic.
Results: I found only one study looking at the direct association between posture during defecation and hemorrhoids. This study tested the effect of squatting position on hemorrhoids by having hemorrhoid sufferers convert to squat toilets. Eighteen of the 20 patients were completely relieved of their symptoms (pain and bleeding) with no recurrence, even 30 months after completion of the study. This study was undertaken in a very small number of people. Therefore, the results, while highly suggestive, cannot be assumed to provide a firm conclusion. No follow-up studies have ever been published. Rest 7 published studies mention a positive association between sitting posture during defecation and constipation. Four mechanisms have been suggested as to how squatting prevents constipation: (1) the weight of trunk presses against the thighs and compresses the colon; (2) the ileocecal valve is properly sealed, allowing the colon to be fully pressurized in the squatting position; (3) Squatting relaxes the puborectalis muscle which normally chokes the rectum to maintain continence; (4) Squatting lifts the sigmoid colon to unlock the kink at the entrance to the rectum.
Conclusion: More studies are needed to clearly define the association between posture during defecation and hemorrhoids. Squatting might prove to be a cheap preventable measure for hemorrhoids, thereby improving the quality of life of millions. This may also cut the costs of hemorrhoidectomies, which is such a common procedure these days.