Malabsorption anemia and iron supplement induced constipation in post-Roux-en-Y gastric bypass (RYGB) patients

Over 250,000 bariatric surgical procedures for the management of morbid obesity are performed in the United States annually. The Roux-en-Y gastric bypass (RYGB) is an effective bariatric procedure because of its efficacy in achieving significant weight loss, low complication rates, and outcomes in reducing cardiovascular and all cause mortality. Because food bypasses the portion of the small intestine whereby micronutrients are normally absorbed, micronutrient deficiencies following surgery may lead to iron deficiency anemia. Iron deficiency anemia is estimated to occur in 6%-50% of post-RYGB patients. Consequently, the procedure requires lifelong behavioral change to ensure therapeutic iron supplementation.

A nonsystematic literature search for clinical guidelines, review articles, and research was conducted.

Clinical recommendations include prophylactic iron supplementation with ferrous sulfate to prevent iron deficiency anemia. Ferrous sulfate is a well-established cause of constipation possibly resulting in low patient tolerability and subsequent low adherence rates.

Strategies for managing the side effects of iron supplementation including constipation may require a unique approach based on the anatomical and functional changes in the post-RYGB patient and the requirement for lifelong iron supplementation.