"If you need a laxative when you have a cold"? What? Since when does having a cold "keep the train in the station", as it were? Man, The Forties were weird.
Ex-Lax was trying to win customers over from the more traditional household super pooper mover, castor oil. Everything I know about castor oil I learned from old cartoons, where it's mostly used as a punishment for naughty children, as seen in the brilliant Tom & Jerry cartoon, Baby Puss. The link takes you straight to the castor oil part, but the whole cartoon is a classic. Do yourself a favor and just watch it. FaceTube is full of truncated and backwards copies of this cartoon, so this link goes to some weird hole-in-the wall hosting service that will probably stop working in a week.
Did someone say "gimme that constipated kid clip art"? No? Okay! Here it comes! We're giving you a Graphic Gift with and without the slightly odd "anger lines" floating in the air around the kid's head. You're welcome!