mnemonic (1):- bethanechol = BeThinAndCold (cold emotions to concentrate on racing) Think of a horse jockey. They are notorious for losing weight (ie. using diuretics). So, they would be taking BeThinAndCold.When you want to lose weight, you want to lose as much urine and feces as possible.
Think of a horse jockey in a race. He's desperate to win, so he starts taking BeThinAndCold, thus urinating and excreting to lose weight and Become Thin. He Calls out as he charges past other contenders.
Or, an alternative: think of a horse jockey in the toilet taking BeThinAndCold before a big race, eliminating his urine, thus Becoming Thin. While he urinates or excretes, he is calling(ie. the noises you make when you go to the washroom)

Three Musketeers as jockeys = BeThinAndCold

Bethanachol = BeThinAndCold

- action: activates smooth muscle in Bowel to push feces out, and destrusor muscle of Bladder to push urine out. (1)