HI, thanks for using healthcare magic As the bile from the liver passes through the intestines, it changes and these changes would normally cause the stool to change from green to brown. If a person is having frequent bowel movements, then the bile does not have the time to undergo then normal changes so the stool may be green. Since she is having diarrhea, this is the likely cause of her green stool. Her doctors may want to assess her to determine the exact cause of the diarrhea and weight loss. She may need additional bloods and imaging. A stool sample may also need to be sent to the lab for analysis. Imaging would be of the abdominal pelvic organs looking for any abnormality. Treatment would depend on the cause found. I hope this helps