I'm on a blood thinner. had a heart attack 2 years ago. have 4 stents. have hemorrhoids. there's a lot of blood in the toilet. should i be concerned?

Definitely...: If there is a lot of blood in the toilet, please, go get yourself checked. Obviously on a blood thinner, you are at an increased risk of bleed. So please, go to a doctor, get it checked.

Yes: See doctor may be simple as your inr is up but you may have a bleeding lesion which will be more obvious and dangerous on blood thinners hopefully just your hemorrhoids but still a risk.