Can taking mirilax cause me to go in to labor?

Always a first..: Miralax (polyethylene glycol) is a lavage agent that improves the ease of defecating. I'm not aware of a bowel movement inducing labor, but I guess there's always a first. Its typically best to, & I recommend that you, check with your obstetrician before taking any product to assess if its safe in your unique circumstance.