The anal swelling and heavy legs may be caused by rectal prolapse, anal papillitis, rectal cancer, neighboring organ lesions, mental disorders, etc. The anal swelling and heavy legs may be caused by rectal prolapse, anal papillitis, rectal cancer, neighboring organ lesions, mental disorders, etc. 1. Rectal prolapse: Rectal mucous membrane layer, rectal polyp prolapse and prolapsed internal hemorrhoids and other diseases lead to the dentate line part of the compression and stimulation, so the symptoms of anal distension and swelling of the legs with the urge to go to the toilet. 2. Anal papillitis: dry stool, direct trauma and other factors lead to acute congestion of the anal papilla, edema and other inflammatory lesions, so this symptom will appear. In addition, sigmoiditis and proctitis can also cause anal swelling and swelling, which can lead to the symptom of heavy legs with the feeling of having bowel movement. 3. Rectal cancer: malignant hyperplasia of rectal mucosa tissue leads to the destruction of normal intestinal wall, bleeding, erosion and other changes, so the symptoms of anal distension, dyspareunia and heavy legs will appear. 4. Neighboring organ lesions: pelvic inflammatory disease, prostate hyperplasia, vaginitis, ectopic pregnancy, gastrointestinal bleeding and other lesions involving the rectum, direct stimulation of the outer wall of the rectum, resulting in symptoms of anal distension, bowel movement and heavy legs. 5. Mental disorders: without any organic lesions, it may be related to mental stress, emotional excitement, autonomic disorders and other factors, the nerve function disorders of the anal sphincter, pelvic floor muscles and other muscle tissues, so there are symptoms of anal distension, bowel movement, heavy legs. Anal distention and swelling, the old with stool legs sinking may be related to a variety of factors, it is recommended to consult a doctor in time to clarify the diagnosis.