The rectum is innervated by sympathetic and parasympathetic nerves belonging to the autonomic nervous system. The nerves of the anal canal are innervated by branches of the internal pudendal nerve of the somatic nervous system, which are distributed to the anal raphe, external sphincter, anal canal and perianal skin. Therefore, the mucous membrane above the dentate line is slow to feel pain, but it can feel obvious pain when the rectum is distended and pressed. Such as anal sinusitis, rectal tumors and other diseases, often feel severe pain in the perianal area. Because the nociceptive nerves of the lower abdomen and lumbosacral region and the nociceptive nerve innervation center of the rectum are located in the lumbar spinal cord, therefore, the pain of rectal lesions can also lead to pain in the lower abdomen and lumbosacral region. For example, proctitis may manifest as small abdominal pain or lumbar pain. Perianal, abdominal or lumbosacral pain can not be excluded from rectal diseases, we should consult a doctor in a timely manner, improve the examination, and follow the doctor’s instructions to be treated accordingly after a clear diagnosis.