Shooting pain in the rectum is known in the medical field as "Proctalgia Fugax", or "Levator Ani Syndrome".
This pain in the ass affects an estimated 8-18% of the world population, but tends to occur more often in women than in men.
It is believed to be caused by a spasm of the anal sphincter, or the pelvic floor muscles. Low-fiber diets and high caffeine intake seem to be the prevalent causes for the occurrence of these spasms.
While annoying and painful, these spasms are harmless and do not indicate disease.
Ass cramps: a literal pain in the ass | PoopReport.com
i was worried it was prostrate
maybe if i eat more brown rice ill recover