Hello everyone ? Mommies, could you please tell me what to do with my …

Hello everyone ? Mommies, could you please tell me what to do with my almost 3-month-old baby who is always constipated, especially at night, and this prevents him from sleeping. Until 2 months old, he pooped every day then we were giving BioGaia, then he pooped after a week like Play-Doh. Now he's not pooping again, but his tummy is soft! The neurologist says to use enema, she put in glycerin candles, it didn't help ? Yesterday, my husband bought more BioGaia, in the pharmacy they sold it for older children, I didn't look and gave him as usual 5 drops, but it says that you give it to children