The flat green stones are bile from the liver or gallbladder or even ducts not Mercedes stones and the orange stones are more likely from the gallbladder. A fifths of Gallstones are composed of calcium and an orange-yellow waste product called bilirubin. They are unlikely to be 'poo balls" if you have urgent diarrhoea. Rarely the orange stones can from pockets that have developed in the bowel but not green ones. Your signs and symptoms will give some more clues.
Your 'poor' doctor has such a huge ego that he couldn't bring himself to say he didn't know what they were so he made something up. I have seen green balls with constipation but it consisted of small pieces of bile material. Orange stools often indicates that the stool has passed through the gut very quickly but they are not hard.
On my first flush I produced a white radish shaped stone with the appearance of being made from granulated sugar. It was hard with a green centre.