Introducing new foods

 Hello All,
I am 5 1/2 weeks out from my RNY surgery.  Two weeks ago my nutritionist and surgeon advanced me to a stage 3 diet.  I introduced tuna, eggs, soft cheese, and soft chicken to my diet.  All seemed to go well for about a week when I experienced horrible consitpation, stomach cramping, and nausea (without throwing up).  I could literally feel the food moving down through my new stomach and sitting there ****il I dealt with the constipation).

My surgeon took me back to a stage 2 diet for the past week and it has gone well.  I decided to try to reintroduce ONE food again and only at one meal a day.  So, yesterday, I had stage 2 for breakfast and lunch, and then tuna for dinner.  I, again, experienced pretty painful stomach cramping.

I chew my food very thoroughly, and eat slowly--- and the pain usually starts several hours after I eat (during digestion).  My surgeon has been very supportive but I know that the goal is to be getting my protein and nutrition from real food (and not my protein shakes)--- however, I am becoming increasingly worried about eating soft stage three foods.

Has anyone experienced this before and do you have any advice about how to proceed with reintroducing foods?

Ryan