A Retrospective Chart Review of the Hematologic Consequences of Roux-en-y Gastric Bypass Surgery.

Roux-en-y gastric (RYGB) bypass surgery has become increasingly common as a procedure to control overweight/obesity. Due to the resulting bypass of significant amounts of gastric and duodenal mucosa, patients may develop anemia. We reviewed charts of 28 patients who had undergone RYGB surgery in the past 5 years who were referred to us for evaluation. Eighteen of these patients had no hematologic consequences as a result of the surgery. Five patients were anemic but were excluded because they had other causes for anemia than the bypass surgery: myeloma (1), pregnancy (1), breast cancer (1), and heavy menstruation (2). The remaining 5 patients however revealed hematologic abnormalities an average of approximately 23 months following RYGB surgery. In our retrospective chart review, we found anemia most commonly caused by iron deficiency although 1 patient had B12 deficiency, and we suggest periodic follow up of patients months to years after such surgery to screen for anemia from potential malabsorption of iron or B12 from this surgical alteration of gastrointestinal anatomy.