A comparison of the expulsive pressures during defecation in the sitting and the squatting postures showed  that the average man strains 2-3 more in the sitting than in squatting posture (1,2), The explanation lies in the dynamics of the recto anal angle. The lower part of the colon is called the rectum and serves as a collector of feces. The rectum further continues to the anal canal through which the feces are expelled out of the body. There is on average 90 degree angle, common to mankind, between the rectum and the anal canal which forms a lock preventing expulsion of feces during daily activities. The only situation in which the recto anal outlet is straightened is the squatting posture. The defecation in the sitting posture demands excessive effort in order to overcome the recto anal angle and thus has potential for self destruction. From elementary mechanics it is well known that any system that is exposed to excessive pressure will eventually be destroyed. Several human systems must sustain injury, some of which are listed on this site. The final dimensions of the damage to human health will be clear only after many years of following up the change of the Western population to the squatting defecation posture.
A revolutionary new squating device was designed which can be seen on the page: video-film of the new squatting device.

1. Sikirov Straining forces at bowel elimination Isr J Med Sci 1989; 25:55-56
2. Sikirov Comparison of straining during defecation in three positions. Digestive Diseases and Sciences Vol. 48, 7, pp 1201-1205,2003
   ======================================================================================================================================