* Well, all three control the amount or strength of the acid that is produced in the stomach, which of course gives the relief that so badly needed. However, concentrated stomach acid is an essential requirement for the breakdown and subsequent digestion of food. They also have a controlling effect on bacteria that inhabit the digestive system. So continually reducing its production must have an adverse effect on nutrition and health in general.
* Then there is the very real concern about chemicals and drugs in conventional medication, which we hear about regularly in the media. There is always the possibility of suffering the adverse, potentially harmful side effects that these products are known to produce.