In article ,
Phred wrote:

There don't seem to be similar commercial products from the _Cassia_
that I noticed, though the page I previously mentioned
http://www.hort.purdue.edu/newcrop/duke_energy/Cassia_fistula.html
lists a lot of applications under "Folk Medicine".

There's also senna:

sen-na n. 1. Any of various plants of the genus Cassia, having compound
leaves and usually yellow flowers. 2. The dried leaves of C. angustifolia
or C. acutifolia, used medicinally as a cathartic.[NLat. Ar. sana']

According to some elderly (and not so elderly) friends, it was a common
ingredient in the "spring tonics" inflicted upon them by their well-meaning
mothers. Senna "pods" are used as well.

Although most Cassia spp are tropical, C. marilandica ranges well up into the
temperate zone in the eastern US, and is or was used for the same purpose,
although it's mostly grown as an ornamental now.

Btw, use of purgatives is a Bad Idea. Your guts get lazy and you end up
needing higher and higher doses. If a diet high in fiber (whole grain and
vegetables -- brown rice is especially effective) and plenty of water
doesn't work, you need to see a doctor. And it isn't necessary to defecate
every day to be healthy.