I am 20 year old male and sometimes when i get the urge of getting a bowel movement, I sometimes get a sort of spasm like sensation coming from my rectal area…its not exactly a pain, but its a sensation that feels like its sucking in and like a needle prick like at the same time from within…the spasm lasts only like 3 seconds and once i defecate everything is fine.. Is this cause of concern or Is this just normal nerve response from the urge to defecate ?