This is quite a regular occurrence... I hadn't had any bowel movement for 5 days, and then today I woke up with pain in my stomach and feeling very light headed, so I went to the toilet and was in so much pain I could have just curled up on the floor and screamed but I needed to pass stools in order to get rid of the pain. I began to feel increasingly faint and very nearly fainted but managed to stop myself... I was also sweating excessively... The same thing has happened at least 10 times now, and the majority of the time I do end up fainting but somehow today I was able to control it, just about... It's only after I fully 'relieve' myself that I start to feel okay again. Is this anything to worry about?