Chron's Disease, Etiology/pathophysiology: Characterized by inflammation of segments of the GI tract.It can affect any part of the GI tract. Cause is unknown. Most often affects people 15 to 30 y.o.a. In early stages of Chron's tiny ulcers form. Over time, horizontal rows of these ulcers fuse w/ vertical rows, causing the mucosa to take on a cobblestone appearance and scarring occures. Malabsorption of b12 is the major problem when the small intestine is involved. There are many other issues, but this is all I have time for