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

Abstract

Purpose 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. Data sources A nonsystematic literature search for clinical guidelines, review articles, and research was conducted. Conclusions 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. Clinical implications 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.

Changes in gastrointestinal symptoms and food tolerance 6 months following weight loss surgery: associations with dietary changes, weight loss and the surgical procedure

“…However, neither the change in fiber intake, nor the change in water intake, correlated with the change in constipation in the present study. The use of dietary supplements, such as iron, could be another cause of constipation in the post-bariatric patient [ 31 ].…”

Comparison of Oral Iron Supplement Formulations for Normalization of Iron Status Following Roux-EN-y Gastric Bypass Surgery: a Randomized Trial

“…A major observation in the Brolin study was that 21% of patients in the oral iron group did not take their iron supplement regularly (20). In bariatric surgery patients and in the general population, ferrous sulfate supplementation is known to induce adverse gastrointestinal sideeffects (29,39). These observations suggest that non-compliance is a major issue with oral iron supplementation.…”

“…The ineffectiveness of oral iron supplementation for prevention or treatment of iron deficiency may be due to reduced intestinal absorption of iron (25,26) or to low compliance of patients to the regimen (27,28). Users of ferrous sulfate and other formulations of non-heme iron preparations experience gastrointestinal adverse side effects such as diarrhea and constipation because inorganic iron is highly labile (29). However, in a recent cross-sectional study we demonstrated that prophylactic use of oral non-heme iron supplementation was adequate for preserving normal iron status following RYGB (30).…”

Influence of diet and supplements on iron status after gastric bypass surgery

“…It also may be because patients are not well-informed about the need to continue taking iron supplements for the rest of their lives to maintain adequate iron status. In addition, patients may not be compliant with the regimen because the supplements are costly or not well-tolerated; they are associated with nausea and constipation [17,20,21]. Taken together, the influence of iron ingested from supplements and food sources on iron status in patients who have undergone RYGB is not wellunderstood.…”