Today, in the wee hours of the early night I masturbated. And sometimes it happens that whenever I masturbate I start having pain in my anal canal which goes away after certain minutes of times.  Now, few minutes after masturbation I started having an urge to defecate. While defecating it felt as if there is some pain in the anal canal which got bit relieved after I passed the stools. Turning point comes that when I stood up after defecating I felt nauseous and so I inclined myself towards the wall of the washroom but somehow I "fainted" and gained consciousness soon after falling and then I sat for a couple of minutes on the floor and got up. A day before this day I had slept for 5 hrs... What could be the reason? Is it low BP issue or something more? Can masturbation cause anal canal pain and fainting? I didn't do excessive masturbation. I masturbated after 15 days. Kindly help.