I know I couldn't tolerate that much fruit, even if its soluble or not. Maybe you need to add some more "carb" type things, like bakes potato, pasta and more rice. As I mentioned before, too much IF makes my poo's messy and makes me a very stinky, gassy girl!
I think adding one food a week is a great idea. If you aren't any worse for wear, sort to speak, than keep the food and add try adding another one the following week.
-------------------- Taking it one day at a time.....