Hi, I am Dr. Girish K an Orthopod
I think you might be suffering from coccydynia
which may present in this way.
Treatment: Consult a general surgeon
to rule out anal fissure/fistula. Bleeding is usually associated classically with piles and rarely with fissure. If the surgeon rules out anal problem, then it should be only coccydynia.
It is mainly a clinical diagnosis and X-ray wont aid in diagnosis. the problem now after 30 yrs because your stools might be hard or, you might be travelling long distances in the recent past, etc, reasons.
Usually it doesnot need surgery and conservative treatment with seitz bath (hot water to the part) for 30mins twice daily and anti-inflammatory medicines and avoiding hard seat/chair should do good to you. Nothing to worry