At night, anal swelling, this situation should be analyzed for its cause, there are the following common: first, there may be patients with long-term constipation, which leads to fecal retention, once the fecal retention will be manifested as anorectal swelling discomfort, the anal opening of the intention to defecate, but the sense of exhaustion of the bowel movements, general rectal diagnosis can be a clear diagnosis. Secondly, if the patient has previous constipation of the type of exit obstruction, such as puborectal muscle hypertrophy and rectal intussusception, rectal protrusion, can lead to obstruction of bowel discharge, usually rectal diagnosis or fecal imaging can be clearly diagnosed. Thirdly, if the patient has hemorrhoids in the past, in the long-term diet of stimulating foods such as pepper, sometimes lead to hemorrhoidal vein congestion, stasis, swelling, which can lead to perianal itching, anal night swelling.