I haven't had that happen yet - and I hope I don't.
When it comes to when, I eat when I get hungry. What - I found a great site for the ok and avoid foods and when I
Showed this to my dietician (before leaving hospital) she was very pleased and was also familiar with the site. She only found that the caffeine, chocolate and banana restrictions to strict and if they were tolerated then look at them as ok.
As for how much to eat, I use the sample diet as my guide for portions
Hope it helps: http://www.upmc.com/patients-visitors/education/nutrition/pages/diet-after-nissen-fundoplication-surgery.aspx
The portion sizes on that sample meal plan seem like a lot, do you have similar amounts? And is it ok with your wrap?