Bad (crippling) stomach cramps, dark green stool and blood in stool which is often quite loose or hard to go what's happening? (Been about a month)

With blood in stool. You should see a GI and be checked.
Constipation? It may be that you are constipated, then when you go you have to strain a lot, causing some bleeding and then loose stool after the hard stool comes out. Try getting more fiber in your diet, such as whole grain bread, fresh fruits and vegetables. Also, drink more water as this helps also. If no better in a week or so, see your doctor. Good luck!