All my life i had a problem with constipation.i eat a lot of fibers&healthy whole foods.i consume between 3 to 5 liters of water daily.if i skipped that amount of water i get constipated especially while in ramadan.is there a cure for what i have?

There are some things to try. Sometimes the large intestines stretch out (balloon) when stool is held back & this reduces their muscular effectiveness in emptying. Teaching your body to empty more often on a schedule can reduce endpoint ballooning over time allowing better emptying. A water trapping agent like Miralax is sometime more helpful than fiber. It can take a year to straighten this out.