A lump growing on the left side of the anus can be treated after the cause is clarified through rectal diagnosis as well as anoscopy, which can be categorized into the following ways. First, if the pimple is formed due to the prolapse of mixed hemorrhoids out of the anus, as long as the symptoms are not particularly serious, the patient has blood in the stool as well as the pain is not obvious, it can be treated conservatively. Normally after defecation, you need to fumigate and take a sitz bath through warm salt water, which can promote local blood circulation. If the pimple growing next to the anus is more serious and the texture is hard when touching, it needs to be treated by surgery, such as thrombus stripping. Secondly, if the bumps are caused by anal gland infection, they need to be treated by surgery in time to prevent the formation of abscess. Since the causes of anal pimples are different, it is necessary to identify the causes before doing targeted treatment, either through conservative or surgical treatment.