Hi, Thanks for writing your query. For answering your query, I will like to know following :- the colour of the blood in your stools- whether it was bright red or coffee coloured. whether the blood was mixed with stool or present as a streak over the stool. any pain in the abdomen or the anorectal region while passage of stool. Aleve contains Naproxen, which like other painkillers can cause gastrointestinal bleed. You should always take painkillers along with an antacid like Omeprazole 40 mg once a day. Answers to the above queries will help to know the cause and location of the bleed. I hope this is helpful to you. Thanks.