Gassy 2 month old?!

Glory

My 2.5 month old has had terribly smelling gas the last few weeks. Prior to that she was pooping multiple times a day, the normal breastfed baby poop... now shes pooping once every few days, which was never normal for her. Her last poop two days ago was a dark forrest green... what is going on?!

UPDATE: She finally pooped and this time it was the normal yellow color but it had chunks of green in it... it literally looked like spinach pieces...?!