Check for giardia first. Does it float? I know, that's a gross question, but if it is green and it floats, it's probably giardia. If you have a pet, make sure it is checked also because giardia can be passed back and forth. Check with a doctor.
thank you for your answer
domply121
I there is no other symptoms just color change then it could be caused by certain foods, different formulas of cow milks,and post nasal drip.If there are more symptoms it could be food poisoning ,giardia, gastritis or different inflammatory bowel disease.