Sticky and smelly anus may be caused by rectal cancer, perianal infection, hemorrhoids, anal eczema, rectal prolapse and so on. 1. Rectal cancer: malignant hyperplasia of rectal tissues leads to destruction of normal intestinal tissues, bleeding, erosion, exudation and other changes, and the invasion and involvement of anus leads to ulceration of anal tissues, so there is the phenomenon of sticky and smelly anus. 2. Perianal infection: perianal damage secondary bacteria and other infections, resulting in local tissue inflammatory reaction, oozing, bleeding and even pus, so the anus is sticky and smelly. 3. hemorrhoids: rectum anus mucosa under the supportive tissues such as venous plexus hyperplasia, resulting in rectum anus mucosa raised, external hemorrhoids breakage bleeding can appear anus sticky smelly symptoms. 4. anal eczema: lack of cleanliness and hygiene in the anal area and other factors lead to skin eczema, manifested as skin corn-like size of pimples, blisters, secondary infection and anal sticky smelly. 5. Prolapse of the rectum: the whole rectum or mucous membrane layer moves down to the anus and prolapses, accompanied by intestinal fluid outflow, so it feels sticky and smelly in the anus. The phenomenon of anal sticky and smelly, may be related to a variety of factors, it is recommended to go to the hospital in a timely manner, a clear diagnosis to give the relevant treatment.