Should I Be Concerned About Excessive Sleep, Decreased Appetite, Cold Extremities, And Diarrhea In An Infant?

Hello, my 2 month old has been sleeping a lot, not eating as much as usual, cold hands & feet and diarrhea. I’ve been to the pediatrician but he brushed it off, I got a chest x ray and blood work and they both showed infection but his pediatrician is saying it’s not.