A purple coloration in the anal area is mostly due to hemorrhoids. Hemorrhoids are formed mainly due to the reason that, there is an obstruction of venous blood return around the anus. Often, venous blood clusters or blood clots tend to form around the anus, resulting in a purple coloration of the anus. In addition to the formation of internal hemorrhoids, hemorrhoids are often easy to prolapse from the anus, the color of the prolapsed hemorrhoids most of the dark red or purple, and will also cause bleeding and pain in the stool. If there is long-term constipation or dry stool symptoms, it will also be easy to form a more serious trauma to the anus, and in some cases can also cause anal fissure symptoms, can also cause the purple color around the anus. Other causes include pigmentation around the anus, caused by the phenomenon of aggravation of the color.