Don't know what to do?

Hi!!! I have a son of 1 year and 5 months and I have been problems with his diapers he uses HUGGIES , I don't know if his allergic ... For the past month his been pinching his butt and he has even bleed because he pinches his butt alot ... I took him to the doctor and they told me that its normal since its hot here but as for meI dont think its normal...