Slippery elm has a very pungent taste to it, and its effectiveness is because it contains polysaccharides and has a mucilage quality.
"Mucilages have been utilised for demulcent activity particularly in inflammatory conditions of the gastrointestinal tract. They may provide a direct soothing effect and provide a protective barrier against gastric acid on the digestive mucosa. Mucilages also have topical emollient properties, and a drawing and healing effect on wounds and lesions."www.mediherb.com/pdf/6042.pdf
If you're purchasing slippery elm, I recommend buying it in bulk at your local health food store. It's wicked cheap and the bioavailability of the cell-wall associated minerals may be greater than that of buying something in a capsule thats been shelved for a duration of time.
I've found that it helped me recover from my flare in february, as I didn't do anything else for treatment at the time. It's typically less than $2 for 1 cup of the stuff measured in bulk.
male, Diagnosed Crohns-Colitis (high eosinophil count) Sept 2011
Gluten Free, 6000mg Turmeric daily, 9oz Aloe Vera Juice daily, VSL#3, 800mg Asacol