How can I help him :(

My 2 and a half year old has had diarrhea for days now. Not like water but every every loose wet and mushy and makes a lot of noise coming out. He had to poop first thing this morning when he woke up and just had diarrhea again during breakfast. He won't finish most if his meals because he always seems to end up needing the potty while he's eating and once he goes he doesn't want to eat anymore . He took one single bite of breakfast today and that was it.

His pediatricians office wasn't much help they just told me to keep an eye on it , whatever that means. And gave no direction or advice. He's normally constipated so they think it may be from his miralax but he's been on that for over a year so I don't think it's that.He is getting his 2nd year molars or at least one that I can see idk if if it's from that.

Is there anything I can give him to help ? I'm trying bland foods but that's not enough plus he won't even really eat.