Klor-Con - why can you NOT lay down foe 30 minutes after taking the medication?

If you lay down the contents of your stomach, which contains Klor-Con (potassium chloride) may come up your esophagus and cause damage. So it is better to stay upright and wait for it to be cleared from your stomach.

Basically you don't want it coming up your gastrointestinal tract. It needs to keep going down.

https://www.drugs.com/klor-con.html