For the past few months I've had painful bowel movements during my period - really painful, just before going, going and just after. I've also had a dull pain in my lower left abdomen - level with my hip bone. I've had back pain at the same level too.
I did a bit of a google and it came up with endemetriosis. My periods can be very heavy at the start, but tail off quite quickly. My cycle is quite short - about 24/25 days.
I've had a fair bit of constipation too - had to resort to taking something which then gave me diarrhoea!
My periods are sometimes painful - usually on the second day. I normally take a couple of nurofen which sorts it out. I have more of the crappy period feelings now - bloated, lethargic etc - than I did when I was younger (I'm 37 now).