The main four possibilities are: 1, internal hemorrhoids, clinical manifestations of anal blood in the stool and anal swelling, generally does not cause serious clinical consequences, but if the complication of thrombosed external hemorrhoids or haemorrhage, it is more indicative of the progress of the disease. 2, anal papillary fibroids, mostly caused by chronic inflammation of the anus is a benign tumor of the anus, generally can not be specially treated. 3, acromegaly, mainly caused by HPV virus infection, because the warts have the possibility of cancer, so if not actively treated, the consequences are more serious. All in all, a lump inside the anus should seek medical attention in a timely manner to clarify the nature of the lump and actively cooperate with specialist physicians for treatment, do not self-medication to avoid further aggravation of the disease, causing serious clinical consequences.