There is a hard object in the middle of the anus after the bowel movement and it can’t go back, it may be caused by internal hemorrhoids prolapse, rectal prolapse, rectal polyps and other reasons. 1. Internal hemorrhoids prolapse: early internal hemorrhoids usually do not prolapse, with the development of the disease, there can be internal hemorrhoids prolapse outside the anus phenomenon. 2. Prolapse of the rectum: the anal canal and rectum may be displaced downward and prolapse outside the anus under the influence of pulling stool. 3. Rectal polyp: If the rectal polyp is large and has a tip, it may prolapse from the anus after a bowel movement. It is recommended that the person who has a hard object in the middle of the anus after a bowel movement and can’t go back go to the hospital in time, clarify the cause of the disease, and carry out standardized treatment under the guidance of the doctor, so as not to delay the disease and bring adverse effects to the body.