Red anus in children may be caused by not paying attention to hygiene, diarrhea and perianal eczema. 1. Do not pay attention to hygiene: younger children, in the poop, wipe the ass did not wipe clean, resulting in fecal matter left in the anus, continued to stimulate the anus, can cause the anus red. In addition, if there are microorganisms in the stool, causing local infection, the anus will also be red. 2. Diarrhea: the typical symptom of diarrhea is an increase in the number of bowel movements, which can lead to fecal matter rubbing the perianal skin and mucous membranes many times, thus causing anal redness. 3. Perianal eczema: If a child has perianal eczema, the anal skin and mucous membrane in the role of inflammatory factors, capillary permeability increases, the surrounding skin can become red. Children with red anus may also be related to other causes, to the hospital as soon as possible, the doctor according to the specific conditions of the diagnosis and treatment program.