You need an expert evaluation to determine the cause of your diarrhea including a colonoscopy with biopsies if you haven't had one. Metformin and escitalopram can cause diarrhea also.

Not a lot of info to be able to determine how serious it is. If there is no weight loss, blood in the stool or anemia, then it's usually not dangerous, but I would need to know how many stools happen per day, how many weeks it's been happening, etc. It could be a side effect to medications, irritable bowel syndrome, an inflammatory condition.