Slippery elm (ulmas RUBRA) is a herb that comes from the inner bark of the elm tree, native to North America. Traditionally, this herb is used to treat diarrhoea, constipation, gastritis, gastric reflux, IBS and Crohn’s disease, but its use as a digestive aid is probably the most popular.
There are many benefits of slippery elm, as it soothes the entire digestive tract as it forms a film over any mucous membrane it comes into contact with. 
It stimulates the nerve endings in the gastrointestinal tract to increase mucin production which improves barrier function against ulcers, excess acidity, ingested irritants and toxins of the gastrointestinal tract.
Slippery elm is helpful for conditions such as IBS and colitis as it has the ability to temporarily reduce inflammation and pain. It is also known to soften and add bulk to stools, so it is useful for both diarrhoea and constipation. 
Nepean Naturopathic Centre – making health easy
- Braun L, Cohen M Herbs & natural supplements: an evidence-based guide. 3rd ed. Sydney: Elsevier Australia, 2010.