What Is Hemorrhoids, External Hemorrhoid Treatment, External Hemorrhoid br br br br External hemorrhoids br br External hemorrhoids lie within the anus and are usually painful. If an external hemorrhoid prolapses to the outside (usually in the course of passing stool), you can see and feel it. br br Blood clots sometimes form within prolapsed external hemorrhoids, causing an extremely painful condition called a thrombosis. br br If an external hemorrhoid becomes thrombosed, it can look rather frightening, turning purple or blue, and could possibly bleed. Despite their appearance, thrombosed hemorrhoids are usually not serious but can be painful.