I. ABSTRACT The clinical presentation of Right Upper Quadrant (RUQ) pain, nausea, and postprandial distress necessitates a differential diagnostic approach to distinguish between mechanical obstruction (Choledocholithiasis), chronic inflammation (Chronic Cholecystitis), and functional disorders (Biliary Dyskinesia). Choledocholithiasis (CBDS) is a structural pathology demanding timely biliary decompression via Endoscopic Retrograde Cholangiopancreatography (ERCP), guided by American Society of Gastrointestinal Endoscopy (ASGE) risk stratification. Chronic Cholecystitis (CC) is characterized by irreversible histological damage and is definitively managed by elective laparoscopic cholecystectomy (LC). Biliary Dyskinesia (BD) represents a functional gallbladder disorder diagnosed by biliary pain and a reduced Gallbladder Ejection Fraction (GBEF), typically below 35%, confirmed by Cholecystokinin-Hepatobiliary Scintigraphy (CCK-HIDA). While LC is recommended for selected patients with BD, the predictive value of GBEF remains inconsistent across studies, demanding meticulous patient selection and comprehensive pre-operative counseling regarding the variable rates of symptomatic relief. Accurate sequential diagnosis—utilizing laboratory markers for obstruction, ultrasound for structural changes, and scintigraphy for functional assessment—is paramount to ensure appropriate intervention and optimize surgical outcomes.