A hard lump at the anal opening is mainly caused by disease, and common causes include condyloma acuminatum, hemorrhoids, rectal polyps, etc. The most common causes include condyloma acuminatum, hemorrhoids, and rectal polyps. 1. acromegaly: acromegaly is a sexually transmitted disease caused by human papillomavirus infection, the patient will appear after the infection of the virus, the skin and mucous membrane superfluous organisms visible to the naked eye. The most common places for these organisms are the penis, the vagina, and the perianal area, which is characterized by a varying size and number of reddish, brownish hard particles. 2. Hemorrhoids: Hemorrhoids are blood-swollen veins in the anal canal or the lower end of the rectum, which are divided into internal hemorrhoids, external hemorrhoids, and mixed hemorrhoids according to the location of growth. The anal cushion or varicose veins are easy to lead to the occurrence of hemorrhoids, thus showing blood after stool, hemorrhoids prolapse and other symptoms, manifested in the anus with hard lumps phenomenon. 3. Rectal polyps: rectal polyps is the mucosa of the rectum to the intestinal lumen protruding elevated lesions, when the external environment and other factors lead to rectal polyps, the patient can be manifested as blood in the stool, the anus appeared pimples, after the rush and other symptoms. To summarize, there is a hard lump in the anus, should be consulted as soon as possible, to clarify the cause of the disease, follow the doctor’s instructions to give reasonable treatment, to avoid delaying the condition.