This is a pilot study to test the hypothesis that polymorphisms that may be linked to cyclooxygenase production may affect the likelihood and the nature of bleeding in patients with ulcer disease. Of the two polymorphism that have previously been studied for links we chose the A842G polymorphims. Of the 50 patients with ulcer bleeding who were studied, 8 had a heterozygous polymorphisms and 42 had the normal configuration. On comparing these two groups. there were no significant differences in clinical presentation except that there was a tendency to have less gastric ulcers among those with the A842G/C50T polymorphism. Based on these studies we need to undertake a larger studies comparing these groups with those with ulcers without GI bleeding and those without ulcers