This post will be related to previous one which said that sitting is bad for you. Sitting makes your body form a position which, held for a long period, is unhealthy can may even bring early death. It turns out that in most of the western world you sit when you shit - and this can cause problems.
Most people in the western world are familiar with the sitting toilet - you sit on it like a chair (you're probably doing it right now). Now there is a problem with pooping in this position - namely that you are forming an angle between where the poop is and where its going to come out. And when sitting or standing there is a muscle that contracts to prevent accidents. According to some experts when poop tries to come out this way it can strain the bowel and cause veins to swell leading to hemorrhoids.
The best way to poop is by squatting and this is the method use in most of humanity's history and by people in the non-Western world (namely, those that don't have access to a sitting toilet).
Source: (slate.com) How bathroom posture affects your health.