Proton pump inhibitors (or PPIs) are very widely prescribed medications that arte most commonly used for gastro-oesophageal reflux disease (often abbreviated to the acronym GORD). They are also used for the treatment of peptic ulcer disease, dyspepsia and other conditions where reduction of stomach acid is required to prevent ulceration or bleeding of the gut. Under some circumstances, treatment with other medications may create an unacceptably high risk of GI bleeding (e.g. the use of anticoagulants such as warfarin in the presence of other risk factors for GI bleeds), and under these circumstances it is often the case that PPIs are prescribed to lessen the risk of serious bleeding.
