How do you treat hard stool without constipation?

Someone in my family has very hard bowel movements that often block up the toilet. He already drinks a lot of water and eats a lot of fruits and vegetables, and doesn't experience constipation or any difficulty…just toilet blockage (and it's not the toilet because it happens in all toilets). I assume it's because his intestines are taking too much water out of the stool but since he already drinks a lot of water, etc. I don't know what would help. Anybody dealt with something similar?

He can use a stool softener. Docusate sodium can be purchased over-the-counter in supermarket pharmacies and drug stores. Your family member should also consider that he may be taking in too much dietary fiber. Try cutting back.