DS has been having rather runny nappies for the last couple of days, and yesterday his bum became really red and sore (all round his willy, balls, leg creases right down to anus). He screams with pain when I clean the area, but doesn't seem in pain before/after. I have been smothering the area in Sudocrem but there has been no improvement. It is not helped by him filling his nappy in the middle of the night, so that when I change him in the morning, he has obviously been lying in it for maybe hours.
Should I take him to the doctor - for both the runny nappy issue (is it teething or something more serious?) and the soreness? Or is there something else I can apply to heal the soreness.