My father wakes every few months in severe pain, up in back passage. but he refuses to go to the doctor as he won't allow any initiative testing?

Proctalgia: Proctalgia fugax is a common and benign cause of recurrent significant anorectal pain. The pain episodes are usually short pulses lasting seconds to minutes. It is poorly understood but thought to be caused by spasm of the pelvic floor muscles. Warm water sits baths may help. I suggest your father go see a doctor to rule out an other problems.