What is the cause of anal swelling when standing and lying down?

There are many causes of anal cramping, including factors such as pressure on the rectum.
For example, when the body is standing, the local rectal mucosa of the anus relaxes to form a feeling of swelling, while when lying down, the sagging mucosa can be recovered and the volume of the internal haemorrhoid is reduced, at which point the symptoms of anal swelling are reduced. However, a reduction in symptoms does not mean that the cause is eliminated and it is recommended that the cause is identified and treated when such symptoms occur.