Brief Answer: Go to hospital immediately : Its MEDICAL EMERGENCY Detailed Answer: Hi there, Thanks for your query. From the brief information provided, there is apparently an ongoing bleeding in your stomach as a result of superficial ulcers' formation caused by Naproxen. Naproxen causes irritation and damage to the inner lining of the stomach and duodenum. If these ulcers bleed, the blood- while passing across the entire intestine- gets digested and is the cause of tarry black stools. It is a great cause of concern if you have been having tarry stools since the past 2-3 days or more. Depending on the amount of bleeding inside the stomach/duodenum, you may even require blood transfusion and specific therapy to stop bleeding. STOP NAPROXEN FORTHWITH. IT IS A MEDICAL EMERGENCY. Consult your doctor IMMIDIATELY and apprise him of my opinion. I am certain that he will agree with my opinion; hospitalize you and treat you accordingly, including blood transfusion if required. Hope I have addressed to your concerns to your complete satisfaction and you find my response helpful and informative. I will be happy to answer further queries, if any. Fond regards and have a nice day, Dr. Rakesh Karanwal

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