Colon Cancer But Had Colon Removed For J-Pouch 19 years Ago (UC)

I had ileostomy 19 years ago due to UC - had lost 55 lbs and 22 blood transfusions. Then J Pouch - It was a long period of adjustment, but had no regrets whatsoever.  About six months ago it started to be more painful then usual sitting,  getting worse every day.  I had a CT scan, at one time they tried to  drain the lump.  These were at world reknown hospitals.  I ended up going to the emergency room of one of the colo-rectal surgeons in area.  I went today and still in shock - and they are still going over pathology etc.  Doctor said I had colon cancer and even he was mystified, when I have no colon.  All of the sudden Evidently it is around the lump.He wants to put me in for chemotherapy and radiation - and mentioned I may loose some of my hip bone?? -  I am going to see the oncologist Wednesday as when I saw him a few weeks ago he said there was no need to worry as did my family Doctor.  I think they thought I was a hypochrondriac - - Oh yes, all Doctors but one wanted me to remove my rectum - 19 years ago - but a young intern said to do what I felt best - and a great military reserve Doctor specialist stepped in and saved my rectum.   I kept insisting something was wrong with my CEA?? high blood work - but was told that was due to the type of surgery I had had - etc. misc.  I feel like I am in one of those hospital spinning doors - I had to push the Doctors because of my consistent pain.  Unfortunately I was brain drained as Dr showed me the pix  but did not ask him those questions weighing on my brain today.   Thanks for "listening"