Dairy free brestfeeding/mucus/solids

My son is dairy free due to an intolerance. His poops havent been normal since about 6 wks. They inprove and get better but conatantly change.

With that being said, i am a FTM and dont really know what regular poops are with introducing solids. I can tell his tummy doesnt like some stuff (sweet potatos caused a ball of mucus). But when introducing new stuff does your baby get a little bit of mucus in their stool or none? I feel like if some mucus isn't normal than i will need to cut back the variety of solids and stick with just a one or two things for longer periods?! Just looking for thoughts/experience.