Colon cancer t2

I had a colon reconstruction and histology showed that I had 3 out of 34 lymph nodes infected. I was advised that chemotherapy was my best option but only increased my chance of it not spreading by 15%. I opted for chemotherapy. First intravenous and the rn 14 day’s oral. I had a reaction whilst having the intravenous and after only 3 days of oral my body totally rejects the tablets. They will not stay in my body. I am waiting to see oncologist again next week but just wondered if anyone else had had this problem. I have been very unwell with the chemotherapy but I’m normally a very fit and active 70 year old