Meimi
I used to be a Cambridge Diet Counsellor and I would tell you to steer clear of using the Cambridge Diet after your op, it would not be a good idea. This operation is to help you change your way of eating for ever, the Cambridge Diet does help you lose weight but it is not a permanent method.
I gave up counselling because time and time again clients would lose the weight and put it straight back on again when coming off sole source. I lost 19stone using Lighter Life and the Cambridge Diet and put it nearly all back on within 2 years.
I would only recommend the Cambridge Diet for a quick fix, i.e. losing some weight for a wedding etc.
Your body and the way you see food will completely change once you have had this op, you will not have to use the Cambridge Diet anymore. Think of the plus's you will have, Cambridge ain't cheap for a start, think of the savings you'll make. Also I know from experience the side effects Cambridge can have, hair lose, serious constipation, fatigue, freezing cold hands and feet, and more seriously, dehydration and gall stones.
I have struggled with my bypass, but I can honestly say I would chose a bypass over using the Cambridge again any day. It made me miserable and more obsessed with food in a whole new way.
Hope this helps.