High blood pressure medications. Chronic constipation is a side effect of an older class of high blood pressure medications called diuretics, which act on the salt in your body to control fluid levels.
You get dehydrated and your body steals moisture from the stool," says Krevsky. You cannot compensate by drinking more water than you need — you’ll just lose it through urination. The solution is to talk to your doctor about a switch in blood pressure medication or adding a laxative.
Blood pressure medications: This will depend on which one you are taking but diltiazem and verapamil (calcium channel blockers) and beta blockers (drugs ending in –ol like atenolol) may very well constipate you