I accidentally had a bit of whole flaxseed one month post op. Will I be okay? I am worried about seeds getting stuck in the staples or something like that.

No, but they may be more difficult to digest in that form. If you want flax seeds (I love them in oatmeal), whiz them with your blender or food processor to turn the into meal before adding them to your food.

Perhaps ask your surgeon? I have been using chia seeds frequently since 3 months post-op. I think they were ok once I reached a normal food diet.