The endoscope is a tube which is passed into the food pipe, stomach and the starting portion of the small intestine. Gastritis, esophagitis, ulcers, cancers, bleeding spots, hiatus hernia, lax sphincter etc can be diagnosed. The patient has to be on empty stomach (clear fluids like water or glucose water are allowed). The procedure is painless. Duration is 2-5 min. It can be done with or without sedation. During the procedure, biopsy may be done to detect Helicobacter pylori, the bacteria which causes ulcer and cancers (by rapid urease test or RUT).