Nectar Protein

is the citric acid in this bad for our pouch? 

No, I don't believe so.  I asked my doctor about taking vitamin C megacaps after surgery (extras I needed to get rid of), and he said it might promote healing. ETA: He did have some concerns about citrus fruit early out, because the fruit nodules can get stuck and work on one section of the stomach.  But those concerns aren't present for a liquid.