How long does it take for Lamisil to get out of the system if one gets diarrhea?

Diarrhea is a fairly common side-effect of Lamisil. You should check with your doctor to see if you should keep taking the medicine. If you stop treatment the diarrhea should go away. If the diarrhea is not going away go back to your doctor.

Lamisil will last for sometime in your system as it is slowly eliminated from tissues such as skin and adipose (fat).
See: https://www.drugs.com/pro/lamisil.html