Repetitive hypnic jerk followed by rectal spasms

[Alexander_25]

Whenever I am about to feel asleep I have a spasm on my hand or feet and right after I have rectal spasm.
The problem started right after my visit to my gastroenterologist for hemorrhoids appeared for the first time. After the routine check, my life has become a nightmare. Because I cannot sleep.



So I suppose the problem must be neurological at the pelvic floor. 'Cause there is where it all started around a month ago.  

I personally think, as a non expert, that a nerve down there might got damaged, so when the signal is send for me to sleep, it cannot pass through that damaged or trapped nerve and comes back as a spasm (whether a hand spasm or feet spasm) and thus right after I have the rectal spasm. Does this make any sense?

Can an MRI show if there is a damaged nerve at the pelvic floor?