Medical follow up after bariatric surgery: nutritional and drug issues. General recommendations for the prevention and treatment of nutritional deficiencies.

This review is an update of the long-term follow-up of nutritional and metabolic issues following bariatric surgery, and also discusses the most recent guidelines for the three most common procedures: adjustable gastric bands (AGB); sleeve gastrectomy (SG); and roux-en-Y gastric bypass (GBP). The risk of nutritional deficiencies depends on the percentage of weight loss and the type of surgical procedure performed. Purely restrictive procedures (AGB, SG), for example, can induce digestive symptoms, food intolerance or maladaptative eating behaviours due to pre- or postsurgical eating disorders. GBP also has a minor malabsorptive component. Iron deficiency is common with the three types of bariatric surgery, especially in menstruating women, and GBP is also associated with an increased risk of calcium, vitamin D and vitamin B12 deficiencies. Rare deficiencies can lead to serious complications such as encephalopathy or protein-energy malnutrition. Long-term problems such as changes in bone metabolism or neurological complications need to be carefully monitored. In addition, routine nutritional screening, recommendations for appropriate supplements and monitoring compliance are imperative, whatever the bariatric procedure. Key points are: (1) virtually routine mineral and multivitamin supplementation; (2) prevention of gallstone formation with the use of ursodeoxycholic acid during the first 6 months; and (3) regular, life-long, follow-up of all patients. Pre- and postoperative therapeutic patient education (TPE) programmes, involving a new multidisciplinary approach based on patient-centred education, may be useful for increasing patients'long-term compliance, which is often poor. The role of the general practitioner has also to be emphasized: clinical visits and follow-ups should be monitored and coordinated with the bariatric team, including the surgeon, the obesity specialist, the dietitian and mental health professionals.