Internal hemorrhoids can appear within the rectum, but unlike external hemorrhoids they are usually painless because the nerves inside the rectum only register pressure, not pain.
Internal hemorrhoids can sometimes bulge down outside of the anus - if this happens it is called a prolapsed hemorrhoid. The hemorrhoid may return tot he anal canal or rectum on its own, or it can be pushed back inside with a finger. It may prolapse again though following another bowel movement.
Prolapsed hemorrhoids can sometimes be painful.