Is green poop normal after galbladder surgery?

Yes, briefly: Bile contains bilirubin, which is normally golden in color. In the intestine, most of bilirubin is converted to stercobilin which is responsible for the brown color of human feces. Certain bacterial enzymes convert bilirubin to biliverdin, which is green. After gallbladder (or other gi) surgery, changes in the balance of bile, bacteria and GI motility can result in transient color changes.