As writer Will Black discovered, you just need to reposition your leg.
The samurai would sit squarely on the seat, cross his leg so that his right ankle rested on his left knee (his left foot remained on the ground), place a hand on each knee, then straighten his back. Supposedly this aligns the bowels to help one from having to strain. You may think it seems like a bunch of malarkey, but this one actually works. If you have ever felt like there is a plumbing issue when you sit down, then pay attention. Take your time, have some patience, and you will get the yoga version of Draino on your system that has been passed down from samurai warlords of old. I have literally felt a swirling sensation during the act of evacuation. Try it out to see for yourself.
http://www.artofmanliness.com/2014/03/19/how-to-poop-like-a-samurai/