Agrimony contains a large amount of tannins which means it can "dry up" issues like diarrhea . This is a very old herbal remedy with a history of being used in the middle ages for battle wounds.

You can make a tea of this herb to treat mild diarrhea, use 2 teaspoons per 8 ozs of boiling water. It can be used up to 4-6 times a day.
The tea can also be used as a mouth rinse or a gargle when you have a sore throat.