That sucks @Lmc1310 If anything is going to upset your colon, the taxol drugs will do it. I can understand why there is reluctance to put you into that program while there is something else going on. What that something is will be more obvious after the next scan. No point telling you not to worry in the interim.
As I found out, upset colons during treatment are a real problem that can see you literally starving for months because you can't absorb many of the nutrients you need. Not a good thing for your body or mind. That's without the pain, which it sounds like you have had a taste of.
Three weeks doesn't sound like a long time, but it is when you are trying to keep your life together. Bless those who think that platitudes are helpful, even though they the surest way to make me think you are simple minded. Right up there on the top of the list is "Stay positive, you're strong, if anyone can beat it, you can." The only response I want to give to that is a display of strength such as giving them a whacking great head butt.