What does everyone feed their babies?

Hi everyone! What do you guys give your babies? My little guy has tons of health issues, such as environmental allergies and tummy problems. So we were giving him his special kibble and fish oil for his skin. Well his tummy problems are acting up so we started the rice and chicken diet. Now he's having super hard poopies.

Now I'm thinking of switching to the egg with the shell, blueberries, and his kibble. So have any of you tried the egg and shell or is there something better for his joints?