Diminished or absent anal reflexes indicate bilateral pyramidal fasciculus or cauda equina nerve damage. Cauda equina damage is a common clinical condition, mostly due to absolute or relative stenosis of the lumbar spinal canal due to various congenital or acquired causes, resulting in a series of neurological dysfunctions due to compression of the cauda equina. If the cauda equina nerve is damaged, the anal perineum and lower extremities may experience heteroesthesia, burning pain, and in severe cases, urinary and fecal disorders. This causes great inconvenience to the patient. What are the examination methods for the weakening or disappearance of anal reflex? 1, anal reflex The anal reflex is a shallow reflex in the human nerve reflex. When a person lies down, holds the lower limbs up straight, and crosses the perineum with a small needle, the external anal sphincter will contract. If the patient’s perineal skin around the anus is lightly stroked with a cotton swab or lightly pricked with a large-headed needle, the anal contraction will be seen immediately when normal. If the above response is delayed or does not occur, the anal reflex is weak or absent. There is no need to be too shy or nervous during the examination to avoid affecting the examination results. 2.Anal finger test An anal finger test (citation) is a simple and easy but very important clinical examination method in which the doctor uses a finger to stick into the patient’s anus to check the disease. Generally speaking, anorectal finger examination can be divided into two parts: external and internal finger examination. Rectal cancer can be felt as a hard mass with uneven or cauliflower-like surface, pus, necrotic tissue and dark red blood, and the intestinal cavity feels narrow, and the finger stained with dark red blood. The examiner lightly scratches the patient’s perineal skin around the anus with a cotton swab or lightly pricks the patient with a large-headed needle, and when normal, the anus is immediately contracted. If these responses are delayed or do not occur, the anal reflex is diminished or absent. In case of cauda equina nerve root damage, various symptoms of nerve damage below lumbar 2 may be manifested. In the case of total cauda equina damage, the sensory impairment is clearly delineated, with the upper boundary being the groin in front and the level of the superior iliac bone in the back. Below this, sensory impairment occurs in the buttocks, perineum and all lower extremities, accompanied by spontaneous pain (electric shock pain), abnormal sensation in the perineum and radiation to the lower extremities, and often a painful sensory delay. The height and degree of cauda equina damage varies. Its upper and lower boundaries may vary. It has been reported that the recovery of motor function is better than the recovery of sphincter function, while the recovery of sensory function is the worst. The recovery of sphincter function is better in patients with urinary retention than in patients with urinary incontinence.