Diverticulosis and after first chemo

My BC had returned in my DIEP flap reconstructed breast after a 13 year remission. There was no spread or lymph node involvment, but because of it's return and an oncotype number of 28, it was suggested that I undergo chemo and radiation. Something I had not had to do in the past.  I thought that I was fairly healthy otherwise with some minor issues, one of which was IBS or so I thought.  I had been having a pain on my lower left side with diarrhea but attributed it to my IBS and my oncologist was unconcerned.  I did have an cat scan and bone scan before my surgery and also mentioned the pain to my surgeon and was told that the cat scan didn't show anything. 

I had my first chemo treatment and the next 3 days had some diarrhea, like I was used to but a bit worse.  This may sound stupid, but I was so used to having it that I didn't take Imodium and thought it better to be cleared out than stopped up.  After 3 days, I was feeling better and not having anymore diarrhea.  But on the Sunday, the 5th day, I had bad left side pain and some strange spine cramping pain.  I called my oncologist office which is about 2 hours away and they said I should go to the ER.  Once there, I had a cat scan that showed acute diverticulosis and my potasium level was critically low. My oncologist called when I was in the ER and really made me feel dumb for not taking the imodium, and that I wouldn't be in that position if I had.  I spent 2 days in the hospital getting antibiotic IV's and was on a liquid diet. 

When I got home, I called my oncologists office and they said to call them and let them know how I am the day before I travel the 2.5 hours for my next chemo treatment and they would decide what to do.  Now I've got about a week and a half to get in to see a Gastroenterologist locally to get a better handle on what's going on with my gut. I'm not sure that I'll be able to get the full story before my next schedualed treatment. In the mean time, I'm feeling better but trying to learn how to eat to combat either the diarrhea or constipation from imodium.

Has anyone else had diverticulosis while undergoing Chemo?  I'm concerned that becasue I'm doing this chemo as a precaution against recurrance that maybe it may be more of a risk to continue foreward with it.