The current toilet seat is a comparatively new invention. It was developed in the Industrial revolution by people who thought it was more 'dignified' to sit on a 'throne' than the way the natives did. However, many doctors at the time were worried about this causing health problems because it went against nature. If you have ever felt, as many, many people do, that after you have evacuated, there is still something left, here is the reason:

The anal canal is UNSTRAIGHTENED when seated. Bowel evacuation when seated results frequently in OBSTRUCTIVE CONSTIPATION.

Adopt a relaxed, FULL SQUAT POSTURE and the anal canal STRAIGHTENS

Oncologists have observed that 80% of colon cancers occur in the caecum and the sigmoid colon, the two areas that are not fully evacuated in the sitting posture. This causes fecal stagnation and probably explains why colon cancer is the second leading cause of cancer deaths in the United States. In traditional Asian and African cultures where squatting is the norm, colon cancer is virtually unknown!