Local treatment with anti-fungal ointments and meticulous care to keep the area dry will treat the current "rash" that you have. Nevertheless, as mentioned elsewhere there will likely be recurrent episodes of this problem in the future unless the primary cause is addressed. The primary cause is the excess skin hanging down and overlapping in this area. This can be treated by simply surgically removing the excess skin. This is an easy procedure and the recovery is very straight-forward. For a more comprehensive solution which would include a cosmetic improvement in the overall appearance of the stomach including removal of all the excess skin, fat reduction, and tightening of the muscles which become stretched from pregnancy, you could consider a tummy tuck. This would address all of these issues and give you a very nice looking flat stomach. For more information about a tummy tuck please see the web link below.For the best results, seek the consultation of a plastic surgeon certified by the American Board of Plastic Surgery. They have a website listing all the certified plastic surgeons. Members of the American Society of Aesthetic Plastic Surgery will all be board certified in plastic surgery and have demonstrated an interest and competence in cosmetic plastic surgery as well.