Does anyone here have any experience with celiacs disease in kids?

I’ve been doing my research I’m not a doctor but I’m just curious..

My toddler tells me his tummy hurts often lately.

He also has never really had “normal” poop. It’s never been formed I guess you’d say. Always loose. Not diarrhea but not firm.

He’s also got low iron.

Just wondering if anyone has any experience.