Yes it could be. However ecosprin by itself is not strong enough to cause bladder bleeding. He should see a Urologist to make sure there is no bladder tumor or prostate problem.

Aspirin could make him more prone to bleed with a preexisting condition. Please have him checked out by his internist, and then a urologist if necessary. He could have anywhere from bladder infection to polyps, to kidney stones to prostate issues. After a heart attack, it is important to be on an anti-platelet medication such as aspirin or clopidogrel, etc., to prevent recurrence.

There must be something to bleed in order for the antiplatelet drug to precipitate bleeding. He needs to be seen by a urologist.