I have been bleeding from my rectum for the last 3 days

Go to the ER NOW!

Bleeding from any orifice, other then a period, is cause for GREAT CONCERN.

It could be something as simple as a anal fissure, but could be much much worse.

If you aren't bleeding continuously, then the most common reason is hemorrhoids.
That can be handled outpatient with minor, quick surgery. ER not needed.

Hemorrhoids are common if the blood is more when you clean. If there is blood mixed in with the bowel matter coming out, it may well be a more serious issues.

If there is a lot of blood, you need to see the ER, but at any level, you need to see your doctor fast.

I've had anal bleeding for 30 years. Sadly it's due to IBS and internal hemorrhoids (sorry for the tmi).

Most rectal bleeding is due to tearing, hemorrhoids, or something minor.

Do you bleed constantly, or only when you have a bowel movement?

This should be mentioned to your doctor asap, as it could be something serious. Your doctor will likely order a colonoscopy to find out what's causing the bleeding. The ER really won't be able to help you with this.

I will add, based on Joys post, the hemorrhoids can't be handled with a quick surgery. It's not that easy. Surgery is the last option, and you should be grateful for that. Hemorrhoid surgery is hell, very painful, not something you want to go through if you don't have to. First they'll likely try banding, which is not pleasant, and is painful. If that doesn't work then they'll discuss surgery which is even worse than banding, but only if you really need it. It's not done lightly, and it's not quick or easy by any means.