The pain between the caudal vertebrae and the anus may be caused by the following reasons: 1. It may be caused by an injury to the tailbone, which is often seen when the patient falls and receives a direct impact, resulting in a contusion or even a fracture of the tailbone, leading to pressure pain here. 2. It may be caused by a lesion related to the anus, such as a hemorrhoid, perianal abscess, anal fissure, or anal fistula around the anus. 3. It may be caused by prolonged pressure, such as prolonged sitting and standing, and the cushion is very soft when sitting, which may cause protrusion of the fissure into the area, resulting in prolonged pressure on the area, leading to prolonged ischemia and similar symptoms. 4. For example, prolonged diarrhea may lead to skin erosion in this area, which may cause significant pain when the patient presses on it.