PUD, most frequently caused by infection with the bacterium H. pylori or the use of NSAIDs, is a common and costly public health problem worldwide. Because inexpensive, reliable diagnostic tests for H. pylori infection have been developed, definitive testing for H. pylori infection can now be performed by primary care physicians. The infection can be cured by means of a combination regimen that includes selected antibiotics and proton pump inhibitors; an uncomplicated case of PUD does not usually require referral to a gastroenterologist. However, H. pylori is not the exclusive cause of PUD; some patients are now known to have recurrent PUD even after effective anti-H. pylori therapy.