Noted the history about your Father about having pain in rectum and unable to pass stool, past history of pains here and there as you have mentioned.
The most probable reasons I can think about are:
Proctalgia fugax is a known condition and can be diagnosed by examination, investigations like colonoscopy
and so on.
The cause is usually psychological problems.
Ans this can explain the pains in head, ribs and so on.
This can be part of fibromyalgia
and thus related to the stress and anxiety
I would advise him the following:
Consult a Doctor and have proper investigations if needed under the Specialists.
and medications should solve the problems.
If colonoscopy and other investigations show something positive it can be treated accordingly.
Hope I have answered your query. Let me know if I can assist you further.
Dr. T Chandrakant, General Surgeon