Is prune juice better than most laxatives?

It works well: I don't know if prune juice has been compared "head to head" with other laxatives, but it works well. One time i prescribed 2 ounces / day for a patient that was constipated, and within a week the nursing home called back and asked if i could reduce the dose because it was working too well. Now, it doesn't always work, but it surely is a simple thing to try.