IntroductIonThe epidemic of obesity (having a body mass index [BMI] of 30 and above) and its related medical diseases has been recognized as one of the most common public health problems facing the world today. [1] According to the World Health Organization, around 2 billion adults (40%) are classified as overweight, of those 650 million (13% of the total population) are diagnosed with obesity worldwide in 2016. [1] Scotland is one of the most significantly affected countries. In 2018, the majority of adults in Scotland (65%) was overweight, around one-third of those were diagnosed with obesity (28%). [2] Among treatment modalities for obesity, bariatric surgery has been the most effective intervention for sustained weight loss. Bariatric surgery ameliorates obesity concurrent metabolic syndrome in the majority of patients. [3] Laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery is one of the bariatric procedures where restriction and malabsorption of food happen simultaneously. [4] Adequate preoperative workup is essential for the success of bariatric surgery. This workup is not only restricted to exercise, preoperative weight loss or attending a teaching program, but Background and Aims: Patients with obesity are known for higher chances of having upper gastrointestinal (UGI) pathology and diseases. Esophagogastroduodenoscopy (OGD) is considered the investigation of choice to detect and confirm UGI pathology in patient with obesity. The routine OGD as a preoperative workup remained controversial before gastric bypass surgery. The need for preoperative OGD on patients undergoing bariatric surgery has been a subject of debate among bariatric surgeons. The study's aim is to evaluate the impact of routine preoperative endoscopy on patients underwent gastric bypass surgery laparoscopic Roux-en-Y gastric bypass (LRYGB). Patients and Materials: Retrospective review of prospectively kept patients' records who underwent LRYGB in our unit from February 2009 to March 2020. Patients were divided into two groups according to the absence or presence of symptoms before their preoperative OGD: Group A (asymptomatic patients) and Group B (symptomatic patients). Further data on OGD reports, campylobacter-like organism test and histology results and changes in the management plan were collected and analyzed. Calculation of post hoc power and Fisher's exact test was to investigate the correlation between OGD indication and its findings. All analyses were conducted at a 5% critical level. Results: A total of 114 patients included in the analysis, 85 (74.56%) were in Group A and 29 in Group B. OGD detected pathology in 34 patients in Group A and 21 in Group B (P = 0.004). Those included hiatus hernia (HH) (17.65% Group A, 44.83% Group B, P = 0.006); stomach ulcer (7.06% Group A, 3.45% Group B, P = 0.676), Helicobacter pylori (H. pylori) infection (12.86% Group A, 29.41% Group B). This led to change of management in 22 patients in Group A and 12 in Group B (P = 0.157). Those changes included H. pylori eradication (10.59% Group A,...