What causes pain on one side of the buttocks?

Pain on one side of the buttock may be accompanied by symptoms such as perianal abscess. This condition may result from recent chronic constipation or diarrhea, leading to infection of the anal sinuses and anal glands within the anal canal. Subsequently, a suppurative lesion develops, ultimately progressing to a purulent infection. Prompt medical evaluation is essential: an anoscopy should be performed at a hospital, along with perianal color Doppler ultrasound and a complete blood count (CBC) to confirm the presence of a perianal abscess. If diagnosed, immediate incision and drainage of the perianal abscess is required.