My gi dr prescribed me lomotil for diarrhea. i take norco 10-325 for knee pain. he knows i take norco. why would he give another opiate. will it help.

OTC anti diarrhea: Lamotil, is an over the counter med for diarrhea and does NOT enter the central nervous system and does not affect pain but does affect the large intestine to slow it down and help loose stools. Norco an opioid has the same effect on the large intestine and it does cross into the CNS causing pain relief. Technically both meds are in the same family but function differently.