When my daughter was constipated the first time, I was told 2 different things by my pediatrician. I was told that since she was around 4 month to do, the walk, then run movements with the legs. She said to keep switching between walk and run, and do for a few minutes. and do it several times a day. Since they aren't walking and able to help th bowel movement move, you are helping to stimulate it. Plus the babies LOVE this.
THe other things i was told ,was to take a q tip and put it by the rectal opening, but not inside, and massage that area with the q-tip, but have a diaper under them, and be ready.
I have noticed as well lately with my daughter if she gets into area, where she is feeling stressed at all, she won't have her movements normal at all. She has been waking herseflf up in the middle of the night having them, and she has slept through the night for a long time.
So I still do these things, though my daughter walks now. I figure it help out, so I will do it .