It's three little Scrabble words in a row (em, er, and od), it's three little Scrabble words if you spell it backwards (do, re, and me), and the backwards spelling sounds like the first three solfege syllables (do, re, and mi).
"'I can't imagine a physician in any time who doesn't know what piles look like. The ancient Israelites and Egyptians had them, after all.'
'It's in the Bible. Ask Mr. Christie,' I advised.
'Ye've been discussing the Bible wi' Tom Christie? Ye're a braver man than I am, Sassenach.' ...
'Not me. Germain asked me last week what "emerods" are.'
'What are they?'
'Piles. Then said they, What shall be the trespass offering which we shall return to him? They answered, Five golden emerods, and five golden mice, according to the number of the lords of the Philistines,' I quoted, 'or something of the sort. That's as close as I can come from memory....'"
—Diana Gabaldon, A Breath of Snow and Ashes (New York: Bantam Dell, 2005), 66