Hello Becky,
Yes, I had a ulcer that was a bit slow in healing. The radiation does cause damage to tissue, gums, etc. I don't know if it was mentioned to you to rinse and gargle with the combination of salt and baking soda in room temp. water. I did this often each day and it helped with the discomfort in my mouth.
What do you use in the PEG tube. I was using Nutrin 1.5 and needed roughly 8 cans per day to keep my weight up. The easy method to figure the number of calories that you need per day to keep your weight is 12 X your current lbs. = calories per day. I weighed 225 at the time. So 12 X 225= 2700 calories. I wanted to lose a few lbs., so I took in less cans and got down to 210. I used the gravity feed method, so I could get the cans in faster and move on. Adjust according to gain or reduce.
My best to you for a speedy recovery