I am back again and we have discussed your pain earlier also. An isolated diabetic neuropathy is though known but is exceedingly rare. Pelvic floor electromyography and nerve conduction velocity study are good investigation to confirm or rule out neuropathy. So you may contemplate this work up. Meanwhile your doctor can consider Pregabalin or Gabapentin for the treatment. I would also recommend anal manometry to see the sphincter spasm and if there is increased spasm, one may consider Biofeedback which help in decreasing the anal sphincter tone.
Please feel free for your follow up questions.
I can understand about the continuous nagging painful sensation and since this is going on for so long, understandably this is very annoying. One of reason of this kind of pain is pelvic floor problems and weakness. One of the cause to be considered for your pain is levator ani syndrome. Ask your physician to consider this entity. Following investigations are done to confirm the diagnosis;
2) pelvic MRI (already done for you)
3) nerve-conducting velocities and needle-electromyographic studies are used to help evaluate compression or entrapment neuropathy and pelvic floor function.
The treatment is following;
1) electrogalvanic stimulation,
2) biofeedback training,
3) digital massage of the levator ani muscles
4) sacral nerve stimulation
5) physical therapy for the pelvic floor muscles
Pelvic congestion syndrome, Pelvic floor relaxation disorders, Pelvic floor dysfunction too need to be considered for the pain. Though treatment is essentially same. Another entity to consider for your pain would be chronic regional pain syndrome. Apart from the above treatment we had discussed; medications like Gabapentin and Pregabalin are helpful.
It is privilege assisting you.