INTRODUCTION: Marginal ulcers are a common complication that occur after gastric bypass surgery and patients can be symptomatic or asymptomatic. We present a case of a bleeding marginal ulcer in a patient with gastric adenocarcinoma who underwent distal gastrectomy with Roux en-Y reconstruction and D2 lymphadenectomy 2 years ago. CASE DESCRIPTION/METHODS: This is the case of a 64 year old male patient with a history of gastric adenocarcinoma diagnosed 2 years ago and was treated with distal gastrectomy with Roux-en-Y reconstruction and D2 lymphadenectomy along with chemoradiotherapy who presented with bright red blood per rectum. Symptoms began 2 days prior to admission with periumbilical pain associated with nausea and vomiting. He was on 325mg of aspirin for secondary prevention of stroke. Haemoglobin on presentation was 11.5. He had one episode of brisk bleeding in ED and his repeat Hgb a few hours later was 6.5. Urgent bedside colonoscopy done in the ICU showed blood coming from ileocecal valve but is otherwise unremarkable. He was immediately repositioned and upper endoscopy was performed which showed an oozing cratered ulcer with a visible vessel at the anastomosis site. The lesion was 15 mm in the largest dimension and the area was injected with 6 ml of a 1:10,000 solution of epinephrine. For hemostasis, six clips were successfully placed. He was then placed on pantoprazole drip for the next 72 hrs. In total, he received 4 units of PRBC and was discharged after 3 days on PO pantoprazole 40mg BID. DISCUSSION: Marginal ulceration occurring at gastrojejunostomy site after laparoscopic Roux-en-Y gastric bypass surgery is a serious complication. They are most common early after the bypass surgery but can occur as late as 1- 2 years. Endoscopic management has been proven to be superior to both surgical and medical management and needs to be repeated frequently until ulceration healing is confirmed endoscopically.Figure 1.: Ulcer at gastrojejunal anastomosis as seen on upper endoscopy.Figure 2.: Hemostasis achieved by multiple clip placement at the site of anastomosis.