Hematocrits and luminal hemoglobin were measured as markers for mucosal injury in the small intestine. A: hematocrits measured on the day of euthanasia for Control, proton pump inhibitor (PPI), indomethacin (Indo), and PPI/Indo groups; n = 6 per group for Control and PPI groups, n = 7 for Indo and PPI/Indo groups, *P < 0.0001. B: total small intestinal lumen hemoglobin content in Control, PPI, Indo, and PPI/Indo groups. Means ± SE are shown; n = 12 per group for Control and Indo groups; n = 6 for PPI and PPI/Indo groups; *P < 0.001. C: luminal hemoglobin content in Control and Indo groups in the stomach (S) and along the length of the small intestine (SI-1 through SI-10). Means ± SE are shown; n = 4 per group; *P < 0.05.