#AskTheExpert my baby is not pooping since last 4 days, he takes 1 feed of formula milk at night as I think that my milk supply is not enough. is he not pooping due to formula milk? he was completely on breast milk but since last 15 days, I give him one feed of formula. He takes 2-3 feeds during 3-5am and thus I think my breast milk is not sufficient for him, so I have to formula feed him....and he doesn't sleep at night and sleeps during the day time. Please give solution for his pooping. Does formula milk cause constipation? Should I avoid anything in my diet?