A pimple at the anal opening may be hemorrhoids, anal papilloma, rectal polyps and so on. 1. Hemorrhoids: when in hard defecation, violent cough, after a lot of exercise, can make the venous blood vessels rupture, resulting in blood flow and in the perianal subcutaneous siltation, thus forming a round or oval purple lump, manifested as a pimple in the anal opening, can be accompanied by pain. 2. Anal papilloma: it is a kind of chronic hyperplasia, not a real tumor. Anal papilloma can appear in the anal canal, and when it increases to a certain degree, it can fall out of the anal canal, resulting in the occurrence of gray-white lumps at the anal opening. The bumps caused by anal papilloma are hard, usually with a tip, smooth to the touch and not accompanied by bleeding. 3. Rectal polyps: single or multiple clustered grape-like lumps prolapse, can have a thin tip. The color is bright red or pink, with bleeding when touched and no pain. When rectal polyps occur, they can manifest as a lump at the anal opening. It is recommended to avoid prolonged sitting and standing, eat a light diet, drink plenty of water, eat more fruits and vegetables, and keep the bowel movement smooth. If the symptoms are serious, it is recommended to go to the hospital as soon as possible, to clarify the cause of the disease, targeted treatment.