Not quite the same thing, but look for 'enema bag'.... the more old fashioned version of the same concept.... Amazon has over 500 listings, and no indication of prescription being needed...
ex-Gooserider
T-5, ASIA-B Jazzy 1100 Jazzy Select 6 Quickie Q-7 Invacare Mariner Want to make / get a better chair, ideally one that stands.