Concerns About My Son's Gut Health and Constipation - #50495

Hi My 4 year son has gut issues, he dosent poop daily, rather does it weekly once or so.he dosent like yogurt or curd and till 3 he was having lots of milk in the morning and night, I used to mix stool softener with it but stopped it since it will become a habit, he is speech delayed as well, I feel the gut health is causing all the problem, is there any tonic that can be given daily for gut health and help him poop daily. Thank you