If I took Ex-Lax for constipation, but then got reflux soon after (i ate immediately before taking the ex lax) will that make the Ex-Lax not work?

Probably not. If you did not vomit exlax then the medication should be absorbed by intestines and work on constipation. Reflux may not be directly related to exlax but the meal prior to taking the medication.Abiity of ex lax to work also depends on whether you respond to ex lax to relieve constipation. There is high association between constipation and gerd.