I’m going on my first year after diagnosis for Colon Rectal Caner.
My treatment began with my first round of Chemotherapy with a couple weeks between infusions. I had the pump for 48 hours after each session

I was not a candidate for radiation and after speaking with several people who had it I believe I was fortunate
I have a team which meet every Friday comprised of my Gastrointestinal, Oncology specialists and surgeons. To date I’ve declined surgery and opted for a second round of Chemotherapy and now after a complete blood work I’m a candidate for a trial program which is one of the Biologics.
I have had the same extreme pain in my bottom and used multiple medications for pain management
One thing I’ve found is diet makes a big impact on how my body handles digestion and impacts my bowl movements which can cause lots of inflammation and pain
I’m trying to look forward for the newest approaches without resulting in surgeries.
It appears everyone wants to give radiation treatment then Chemotherapy then surgery but after deep research I feel there’s better options but only time will tell

My advice is to get several different opinions I went to Moffitt and FCC Florida Cancer Center and another cancer research center. Make sure all your doctors to communicate with each other as a team.
Once you do that you’ll be able to make the best decisions for yourself.
Best wishes