There are many reasons for anal swelling and uncomfortable: the first one is fecal retention. If the patient is constipated for a long time, it will lead to dry stool, and after the rectum has drained the water from the stool, it will easily lead to fecal stones, which will make the anus swollen. Secondly, the infection of the anal glands can spread down the rectum and lead to submucosal abscesses in the rectum, which can also lead to anal swelling, uncomfortable and sometimes painful. Thirdly, it may be outlet obstruction type constipation, such as rectal protrusion or rectal intussusception. After outlet obstruction type constipation, the stool is obstructed from being discharged and sometimes stored in the rectal anal canal, which will lead to anal swelling and discomfort, and sometimes a feeling of anal blockage.