2 year old frequent loose stool with mucus

My 2 yr old has loose stools and which more often than not contain what looks like mucus. He never really has had a hard stool. His nappys are terrible! He had sallmonella last october in which he was hospitalised for, could he still be getting over that or is it normal for stools to be like that in a 2 year old? I have seen a doctor who was not at all worried, but I am not convinced