Dr in some pronographic movies they were perform fisting .is fisting is a normal sexual activity?what are risk associated with it?is it possible fist

Normal Sexuality: What one person considered normal another considered odd. Fisting is generally practice by a small sub-culture and a relatively rare activity. The risks are transmission of diseases just as any sexual practices, though it may be more pronounced. Also, tearing, ripping and permanent damage to the anus, rectum or colon (in anal fisting) or the vaginal walls can occur