A lump on the inside of the anus that doesn’t hurt or itch can be a symptomatic manifestation of certain diseases, such as hemorrhoids, rectal polyps, condyloma acuminatum, anal papilloma and so on. 1. Hemorrhoids: prolonged sitting, constipation, etc. can cause obstruction of rectal venous return, subcutaneous venous plexus on the distal side of the dentate line appears to be bruised and dilated, or connective tissue hyperplasia to form a lump. 2. Rectal polyps: such as inflammatory polyps, can be secondary to any kind of inflammatory reaction, can stimulate the intestinal epithelium to form a bulging lesion, is a kind of protruding from the surface of the mucous membrane to the intestinal lumen of the mass. 3. Warts: After infection with the human papilloma virus, small reddish papules can be seen around the anus, sharp at the tip, soft texture, will grow and grow more, cauliflower-like, papillary and other pimple-like. 4. Anal papilloma: anal papillae due to feces and chronic inflammation of long-term stimulation increase in size and hardness, stool and even usually off in the anus, is one of the common benign tumors of the anus, touching the hard pimples. A pimple on the inside of the anus may also be caused by other reasons, should be timely to the hospital, combined with other test results, clear cause, follow the doctor’s instructions to deal with.