Internal hemorrhoids are located inside of the anal cavity and are typically painless, though they commonly produce bright red blood on toilet paper during bowel movements.
External hemorrhoids are location on the rim of the anal opening and are commonly associated with itching, burning, pain and swelling. These too will bleed if irritated enough.
Sometimes, internal hemorrhoid prolapse and fall outside of the anal opening if not treated early enough. This would still be considered an internal hemorrhoid and is sometimes called a thrombosed hemorrhoid or a prolapsing internal hemorrhoid.
