I started taking Aciphex but within 2-3 months, I became constipated. I reported this to my doctor, who told me that diarrhea, not constipation
was a side effect of proton pump inhibitors. As I always have problems with constipation and have to watch my diet/fiber intake, etc, I insisted on switching my medication. He allowed me to try pantoprazole. The constipation resolved, but after 2-3 months on pantoprazole, has returned.