Yes I agree with Obianuju, I also think it's the formula. And the hot water drops inside the anus works. I do exclusive for my babies and they still hold in excreta. Bcos I was doing exclusive the doctor told me they won't give her any medication. When she is ready she will poo. Even she held it fro up to 7days I didn't give her any other thing apart from breast milk and she finally excreted.

When bathing the baby, drop hot water inside the anus, not too hot, give the baby Enuf water always, I think is the formula that's causing it.

Since hes not on EBF, Give him enuf water to drink, u shud take oranges and vegetables so he can suck it from u.