Baby Diarrhea?

Rae
My 11 week old has had green mucousy poop the last two days and today it's started to have clear liquid with it. Almost every diaper change is poopy. (He is breast fed and his stool is normally yellow and seedy.) He's not really been himself either as he has been extra cranky and sleepy. No significant fever. Should I have him seen or wait it out? FTM!