I am a 39 year old HIV negative male and have had moderate to severe discomfort of my anus (irritation, burning, some blood with stiff stools) for almost two years. I was treated for anal warts in my early 20's but two doctors could not effectively treat the current condition. I'm concerned this could lead to anal cancer. Should I get checked by another doctor?

You should definitely get this checked out. At the very least, you need an anoscopy. Have you had this procedure? In an anoscopy, a health care provider will look up your butt to get a better idea of what's going on. Depending upon the local expertise in your geographical area, you should see a proctologist (a physician who specializes in that part of the anatomy) or similar specialist. It would be ideal if you could see someone who has some expertise in HIV if your are HIV positive. Your note doesn't specify your HIV status. Most of the anal conditions are readily treatable. If you don't know whom to turn too, then consult some of your local support groups for ideas (e.g. a gay or HIV organization, if you are part of either community). Write back and let me know what is found. Good luck.