What's the "een" in Halloween?
1860, from comb. form of colon (n.2) + -itis.
colitis co·li·tis (kə-lī'tĭs)n. Inflammation of the colon.
An inflammation of the mucous membrane that lines the colon. Colitis is characterized by pain in the abdomen, with alternating episodes of constipation and diarrhea.