It is unlikely that SOD causes diarrhea. If this needs to be evaluated, the best way would be Sphincter of Oddi manometry that is done during an ERCP.
I would first consider malabsorption syndromes. This can include fat malabsorption - which is tested via a fecal fat test.
Another consideration is bacterial overgrowth - which can also cause the symptoms of malabsorption. The gold standard for diagnosing this would be via a jejunal aspirate during endoscopy.
I would also consider a colonoscopy to evaluate for colitis or inflammatory bowel disease which can cause some of the symptoms you are describing.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.
Good Luck.