This is what I learned upon researching slippery elm:

Has been used as an herbal remedy in North America for centuries. Native Americans used the bark to treat wounds, ulcers, gastric conditions, burns, sore throats, diarrhea, IBS, coughs, and other skin conditions. It was even rumored to cause a miscarriage, so caution should be used when taking if pregnant (or not taken at all). 

The tree itself is a medium sized tree, reaching well over 50 feet in height and topped by spreading branches that form an open crown. The red, orange, or brown branches grow downward and the stalkless flowers are arranged in dense clusters. The tree’s leaves are long and  green, darkening in the fall. The bark has deep fissures, a gummy texture, and a slight but distinct odor.

A doctor should be consulted before use due to the possible interaction with other herbal supplements and/or medications. Slippery elm contains mucilage, a substance that becomes slick when mixed with water. It coats and soothes the mouth, throat, stomach, and intestines. It causes reflux stimulation of nerve endings in the gastrointestinal tract leading to increased mucus secretion. The increased mucus production may protect the tract from ulcers and excess acidity. 

It can be taken as a tablet or capsule, a lozenge, finely powdered bark for making teas or extracts, or coarsely powdered bark for poultices. 

Please speak to your health care practitioner for appropriate doses. 

Resource: Mount Sinai