There are many reasons why a swelling may be visible around the anus, and anal visualization, anal finger diagnosis, and if necessary, anoscopy can be placed to observe the nature of the anal meatus and determine the name of the disease. The first one may be a mixed hemorrhoid, which is prone to prolapse out of the anus if it reaches the 3rd or 4th degree and manifests as a soft mass. It is usually a mass of varicose veins that can easily prolapse out of the anus when the abdominal pressure increases or when constipation sets in. If the mixed hemorrhoid is embedded for a longer period of time, it is easy to form a thrombus, and a purple-colored swelling is visible around the anus, usually with severe pain. Secondly, anal meatballs may be rectal polyps and rectal adenomas. If the polyps and adenomas are close to the anus, they can easily come out of the anus and form swellings due to long-term stool stimulation. Third, anal fissure, long-term stool stimulation can easily lead to skin fissures around the anus. Chronic anal fissures have a triad of symptoms, including anal fissures, hypertrophic anal papillae and anterior sentinel hemorrhoids, which generally cause the hemorrhoids around the anus to become edematous, thus forming anterior sentinel hemorrhoids, which can also manifest as a meatball around the anus. This is why the causes of visible swelling around the anus are particularly varied.