Hello dear user! I have gone through your query and understood your concerns! Thank you for sharing them on healthcaremagic. The symptoms you are mentioning make suspect about two things: Infection of your gastrointestinal tract which makes you feel nausea, dizziness, green stools. If you have fevers the infection is confirmed and and it must be treated with antibiotics and other supportive drugs. But what I am afraid for, is Gastrointestinal bleeding and therefore anemia as e result of Nacoprosen. All antiinflammatory and painkiller drugs has side effects in the stomach mucosa. They may harm that and cause bleeding which turns stools into green or black. This is the emergent situation that you have to rule out. Please go to your healthcare center immediately and go for a test called occult blood in stools and a complete blood count to see if you have anemia. I hope this answer was helpful to you! Please kindly rate it as helpful and write a short review about your experience with me! I would appreciate that a lot. Thank you and best regards! DR ERIOL.