E.,
When my son was an infant (now 15 y.o) he had the same problem, what his doctor suggested was to give hime warm applesauce or prunes in the a.m. with his breakfast (the 1st phase type of applesauce/prunes). To date he still has a bowel movement every morning.
Just a question, have you talked to your parents or the fathers parents about this problem, maybe you or your partner had the same problem when you were an infant. Who knows this might be an inheritant situation.
I hope things get better. Enjoy being a new mom, this time will go by so quickly!
Good Luck!
D. Graham