This may all be related to the hemorrhoids. Since you have burning and pain, and conservative treatment has not helped, I would suggest seeing a gastroenterologist. You may need an anoscopy, sigmoidoscopy or even a colonoscopy for diagnosis. You may need sclerotherapy for the symptomatic treatment of hemorrhoids. Sometimes radiation treatment can cause chronic inflammation of of rectum and anus, but chemo is less likely to cause this. This is probably not candida or C. diff. Proctitis would be diagnostic consideration.
I hope this helps. Let me know if you need more info. Please "accept" when done.
Main symptoms of Proctitis are not present, no urge to defecate,no constipation, pus,blood, discharge or cramping.
I will see a gastroeterolgist.