Peptic ulcer disease has 2 main etiologies: 1) Helicobacter pylorus infection and 2) NSAID use. Zollinger Ellison Syndrome causes 1% of peptic ulcer disease.
Hemorrhage is the most common complication of peptic ulcer disease, occurring in 15% of patients
25% of patients over the age of 60 years have an AV malformation.
The most common cause of significant lower GI bleeding in the elderly is diverticulosis or angiodysplasia. That typically presents as painless bright red rectal bleeding.
AV malformations are the number 2 cause of massive lower gastrointestinal hemorrhage.
Rectal bleeding following AAA repair is from aortoenteric fistula until proven otherwise.
