Obesity has become a significant health problem in Canada. It is known to be a risk factor for many diseases, including Gastro-Esophageal Reflux Disease (GERD). When medical efforts to lose weight fail, patients often consider bariatric surgical procedures as the next step. The two most common bariatric procedures performed are Roux-en-Y Gastric Bypass (LRYGB) and Laparoscopic Sleeve Gastrectomy (LSG). The gold standard for diagnosing GERD is Esophageal pH monitoring, as it is the most objective method to document the reflux, assess the severity and monitor the response to treatment of the disease. In the last few years LSG has gained in popularity due to its simplicity and short operative time. Currently the comparison between bariatric surgery and GERD symptoms is very one sided. There are significant numbers of studies with conclusive results that state that LRYGB has a positive effect on GERD symptoms, however there is little evidence that states the same about LSG. This means that the relationship between LSG and GERD is inconclusive. An objective evaluation of GERD using 24 hour pH monitoring and validated CRFs at different follow up time points will contribute greatly to our understanding of what this relationship might be.