What Causes Constipation, Stomach Bloating And Green Oily Stools?

I am 19 y/o female and have been experiencing some unusual bowel problems. It started with me being constipated and having bloated stomach, painful to press on. Over the last few months my symptoms have progressed- my stomach is hard around my belly button, my stools are covered in fatty oily substance. Yesterday I had anal leakage- a dark greeny coloured oil. Today my stools are incredibly oily and converted in this dark oily liquid. I have also been feeling unusually tired I haven t been able to find anything online about a condition encompassing all these symptoms