Intractable diarrhea after colectomy/ileo-rectal anastomosis

My niece is very deperate. Had colectomy w/ileo-rectal anastomosis for Lanes Disease (slow transit) and cannot leave the house because of constant diarrhea. No medications have helped - Lomotil, etc. She is wasting away, dangerously. Anyone had this surgery, had diarrhea, and learned how to control it? We would love specific guidance on diet, medication, anything. Also, she moved after surgery and we are looking for an excellent GI doc/medical center. We will go from New York to Florida to a good specialist/center, but something in Virginia would be nice. Thanks so much,
Lou (***@****)