Bisacodyl
Bisacodyl, a diphenylmethane derivative, is a commonly used over the counter stimulant laxative for occasional constipation. Both bisacodyl and [picosulfate] are metabolized to the same active metabolite bis-(p-hydroxyphenyl)-pyridyl-2-methane (BHPM).  Bisacodyl was patented on 25 September 1956 but has been used as a laxative since 1952.