I have 2 suggestions. I had a permanent ileostomy on October 19 of last year and had several yeast infections, so I am familiar with your issue. Get a prescription for: FLUCONAZOLE 200 mg - 10 day supply and take them all. About the 7th day, things will look much better and by the 10th, you will not have any problems. I would also suggest that every time you change your bag, put stomahesive protective powder around the stoma. I hope this helps!!
Have you seen an ostomy nurse? I have also talked to one, and if you don't change your bag every 3 or 4 days (this is always recommended), this may contribute to your problem. It seems on sites with ostomy issues, men keep them on forever (in my opinion) and cannot imagine having the same one on for a week!!! Just a suggestion, not to mention the odor that would have to be associated with keeping a bag on that long, even using STOP or an odor eliminator.