Not long ago, my grandmother underwent a gastrectomy, since then green secretions pops out of her, why?

Mouth or scar: If green pops out of her from her mouth then it if from bile. If green pops out of her from her wound then she has a fistula and should see her surgeon. If green pops out of her from a feeding jejunostomy that is no longer used then she has a non closed fistula. Hope this helps. If you have concernsake sure you go to the appointment with your grandmother.