Chronic diarrhea--induced by celiac plexus block?

A 59-year-old man had severe chronic diarrhea after a celiac plexus block. The block was performed because of unbearable abdominal pain caused by a benign cyst in the lesser sac. The patient also had diabetes mellitus and was treated with metformin. Thorough investigation and various therapeutic trials failed to detect the cause for the diarrhea or to improve it. Based on the temporal relationship we wonder whether the diarrhea was induced by the celiac block procedure. The relevant literature is reviewed.