Initially established in the early 2000s as a standalone surgical procedure, sleeve gastrectomy has become the most commonly performed bariatric surgery worldwide. However, its growing popularity has uncovered some situations that may require a two-stage surgical approach. Disabling and refractory gastroesophageal reflux and post-sleeve gastrectomy incisural stenosis are among the chronic complications leading to conversion surgery. In such complex cases, the Roux-en-Y gastric bypass remains the gold standard. Recently, the terms recurrent weight gain and suboptimal clinical response have been introduced to clearly define situations of weight loss failure. A suboptimal clinical response is defined as a total body weight loss or BMI reduction of less than 20%, or as insufficient improvement in an obesity-related comorbidity. Recurrent weight gain refers to a regain of more than 30% of the initial weight lost after surgery or inadequate improvement in an obesity-related comorbidity. Several surgeries are possible as a second-stage procedure after sleeve gastrectomy, with indications including inadequate weight loss or nonresolution of obesity-related comorbidities. These options include gastric bypass, biliopancreatic diversion, and transit bipartition. This chapter will explore these various strategies, their effectiveness in this specific context, and their long-term outcomes.