AcipHex or Generic Rabeprazole is used for curing heartburn or irritation of the esophagus with the cause of gastroesophageal reflux disease (GERD). Short term treatment of ulcers of the small intestine is another function of AcipHex. It may be used in combination with other antibiotics. They are used for treating ulcers of the small intestine and stops them from coming back. It is also used for treating conditions when your body is making extra stomach acid (Zollinger-Ellison syndrome). Other conditions can be determined by your doctor.
Answer is simple - its much cheaper and generic rabeprazole is the same as brand-name AcipHex in safety, quality, purpose and strength. 50% of all drug sold in the US are generics. The FDA requires generic drugs to be as strong and stable as their brand-name opponents. However they are not allowed to be looking exactly like the brand-name drugs. In the same time generic medicines do have the same active ingredients. So Generic Rabeprazole is made exactly from the same components as brand name AcipHex.