Irritable Bowel Syndrome Treatment

I’m 5′4 155lbs. I’m overweight. I plan on flushing my system for the recommended 10days. Then starting fresh with a new diet. What is going to happen? like how much weight should i loose doing everything right and how bad are the side affects. I am currently lowering my calorie intake and next week i will be juice fasting. So i am ready for the master cleanse. And should i take probiotics after the master cleanse?