My husband just finished his second round. The first round was a breeze with few very mild side effects. During the break he also started radiation so what followed could be a combo of the two treatments. It was downhill from the beginning of the break on .Blood counts dropped and then bottomed out.Progressive nausea, fatigue, and worst of all uncontrollable diarrhea. Fortunate that each day got progressively worse so he was able to complete all but the last day of the cycle. His onc said they would play around with the dose next round. I hear that the drug builds in your system so it is still there during breaks,but they can alter your fathers dose to make his quality of life much better.The side effects will scare you It's like you are watching them be poisoned right before your eyes ,isn't it. It doesn't have to be that way now that they know what he can tolerate . Dorothy in N.C.