Proper anorectal sensation is required for normal defecation, and pelvic floor receptors are thought to be important in detecting the presence of feces in the rectum. Patients with fecal impaction and overflow incontinence have reduced rectal sensation, and patients with traumatic and idiopathic fecal incontinence (idiopathic fecal incontinence) may have abnormal anal canal sensation. Idiopathic fecal incontinence, or neurogenic fecal incontinence, is due to progressive damage to the nerves controlling the transverse muscles of the pelvic floor and the external anal sphincter, as well as reduced internal sphincter function. Clinical manifestations of absent anal canal reflex: Variable degrees of uncontrolled defecation and evacuation, with loss of control of evacuation and liquid feces in patients with mild incontinence whose underwear is occasionally soiled. Patients with severe incontinence also have no control over solid feces and exhibit frequent anal defecation, which can be avoided if the patient is able to find a toilet quickly enough to avoid soiling his or her clothing. The quality of life and physical and mental health of patients with this disease are often affected by the prolonged wetness and uncleanness of the perineal area of the anus and the contamination of clothes and pants and bed sheets. Loss of anal canal reflex clinical examination: 1, physical examination can be seen in the anogenital perineal area moist and unclean, eczema ulcer scar, perianal skin scar anal laxity, and sometimes can be seen rectal prolapse. 2.Finger examination can touch hard fecal mass or tumor, etc. There can be anal sphincter relaxation and stretching, and its contraction force is weakened or disappeared. 3.Careful examination can accurately determine the site of weak contraction and may show the disappearance of anal canal reflex.