Some doctors (mostly in Europe) use tormentil to treat diarrhea. It is also the main ingredient in Quicklyte, a medication manufactured in the US to treat infant diarrhea. There is a study that found positive results for the treatment of ulcerative colitis: www.ncbi.nlm.nih.gov/pubmed/17881930
I tried tormentil root and noticed a few positive results but it was in a dried form so perhaps that affects its effectiveness. Has anybody tried it? It's quite hard to find.