I didn't have loose stools but I had nausea and a feeling of fullness even after eating very small amounts. But that was not until about 1-2 weeks before I was diagnosed. Stage 3C.
These symptoms can be caused by many things. If you're truly concerned and feel that you have doctors that take your concerns seriously, I'd say get this checked out.
I did not have cysts problems, so I cannot help you there, but I want to share my OC symptoms. Started with occasional loose stool, bloating (gas) fatigue, became chronic to the point that i lost too much weight, couldn't keep anything in my body,,turned out I had ascities caused by oc cells floating around in my abdomen. also in my right lung, had difficulty breathing. Good luck