I Be Had Lower Left Side Pelvic Pain Not To

I be had lower left side pelvic pain not to intense but I can feel it sometimes it on the right side as well. Just started noticing green poop not bright green like a dul green but I haven't eaten any green foods. And at first it seems a little harder to come out but one it does it comes out like normal? What could it be?Im a 40 year old male .