How Can Chronic Constipation Be Treated?

I underwent surgery followed by radiation for who grade 1 Tumor in lower spinal area five years ago. Now I got constipation problem, I am clearing should by cremation once in week. and I am on self catheter for urinals. One year back I got ulcer in right buttock near anus, I tested for sugar levels and is normal and the ulcer is not getting healed. I am using hydroheal AM GEL of Dr reddy s laboratories. There is relief from pain but not getting healed. Kindly suggest me what best I can do to get healed my ulcer and is there any better solution for constipation problem and urinary clearance problem....