Fecal levels of trypsin and α-chymotrypsin in patients with Crohn’s disease (CD) were compared with those in healthy subjects. About one-third of the patients with CD had higher levels of trypsin and α-chymotrypsin than the healthy subjects studied. Patients in whom the ileum was affected had higher median values than those in whom the disease was confined to the colon. Possible consequences of high levels of proteolytic enzymes in feces of patients with CD are discus