No, it activates receptors in the gut cells that let the water in.
Without this bit of sugar, water just passes through, without getting absorbed.
Well, i'd argue your statement should start with the word "yes" then. Sugar, is in fact making the medicine go down (absorbed). My interpretation is that obviously a rehydration solution is just very slightly salty water, the taste is not the problem. But the water running straight through you is. Maybe the phrase could be corrected in this case, "makes the medicine stay down". Hmm