Constipation for my 4yrs old daughter?

My sister had bad constipation when she was little, and the doctor told her to stop eating sugar (anything with sugar in it). Also, about two years ago, I was constipated badly and we used a glycerine bullet as well, but, as you said, nothing happened. We went back to the pharmacy and got the enema that was almost as large as a coke can and used the whole thing (you may only need to use half since she is 4. That worked!