Here are two relevant published abstracts:
Diet (including wheatgrass) and Inflammatory Bowel Disease
http://www.medscape.com/viewarticle/553039
Wheatgrass in the treatment of active distal ulcerative colitis
http://www.medscape.com/medline/abstract/11989836
If you would like to get terrific wheatgrass juice, DynamicGreens.com (our family company) is a great source.