Many times they are related to celiac disease, which is a gluten intolerance. This includes wheat, oats, barley and rye that needs to be eliminated from the diet. You may want to look up about celiac disease on the internet and also dermatatis herpetiformis which is a rash on the buttock area (similiar to boils) that is in connected to the body being gluten intolerant. This also sounds like a good case to see and allergist. The body is reacting to something and an allergist may help also.