Thanks for your advices. I know the procedure of douche, but when I put water in, it is always the case that less water comes out. I know too much water will trigger more shit, so I don't put too much, but it often happens, when I put less water in, (In fact, it not too little, it is as suggested as the infographic) my body feels like I put nothing in, I have no feeling that I want to shit, and I cannot let it out. When I put more, it often goes beyond the limit mentioned in the infographic. So far, I cannot find a proper volume of water to put in.
For you, the water just comes out naturally?