Green stools after eating blueberries are generally normal. Blueberries are rich in anthocyanins, which have a good antioxidant effect. Anthocyanins are dark blue in color, and when you eat too many blueberries, the gastrointestinal tract may not be able to fully digest and absorb them, resulting in the anthocyanins in the blueberries being discharged from the body along with the stool. When anthocyanins are mixed with stools, they may appear green, which is generally normal. Usually, after stopping eating blueberries for 2-3 days, the anthocyanins will be fully metabolized and the green stools will return to normal. If after a period of time, the stool is still green, you need to rule out whether it is caused by upper gastrointestinal bleeding, and you should consult a doctor for examination in a timely manner so as not to miss the condition.