>the Latin root for constipate<

You may want to consider the Latin root of rectitude too - rectus, straight.

So two of your original list of four (key) words are from common and non-scatological roots that also have scatological derivatives. Looked at that way, there is a lot less coincidence going on here than first appears.

Reminds me of a wonderful book I have just finished (Why Flip a Coin? - The art and science of decision making) where the author talks about the human propensity to spot a pattern where none exists. (I recommend the entire book to anyone who gambles, invests or cares about voting and how governments are elected - which may be more than usual at this time!)