That causes evacuation; cathartic; purgative(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "evacuative" in a sentence
"I think they should be daily, and fully evacuative, while the entrenched interests are pushing for "virtual drills" on a semiannual basis, to consist of sitting at one's desk "in a highly alert state of mind.""
"We got out before the mad evacuative rush of people trying to escape Hurricane Dean."