Risek is used to treat and prevent stomach and duodenal ulcers as it reduces the secretion of stomach acid and thus treats gastroesophageal reflux disease. Risek is used to treat indigestion, peptic ulcers, gastroesophageal reflux disease, peptic ulcers associated with Helicobacter pylori infection (stomach bacteria), and peptic ulcers associated with non-steroidal anti-inflammatory drugs. Risek is used to treat a rare condition called Zollinger-Ellison syndrome.