esophagogastroduodenoscopy medical procedure

enteroscopy stomach gastroenterologist endoscopy esophagus intestine small endoscopic gastric muscle procedure treatment achalasia minimally vector gastroscopy invasive disorder mucosa submucosa endoscope esophageal les tunnel nonsurgical sphincter fibers stricture anatomical junction digestive system illustration graphic poster therapy gastroesophageal air balloon body cartoon tiny gut flat tube wall examination camera biopsy duodenum