My grandmother had her gallbladder removed several years back, and since then has had periodic but not frequent vomiting spells. The spells seem to come around after eating spicy or fatty
foods. She has been to several doctors from Memphis TN to Hattiesburg MS and noone can give her any explanation as to why this happens. Also the vomit looks to be thick dark green liquid, if that helps.
After gallbladder surgery, many people cannot process fats the way they did previously and need to stay on a low fat diet. Your grandmother may be one of those people and will need to limit her fat intake.