Levothyroxine
"When I take my Levothyroxine 0.075 mg as prescribed; on an empty stomach, preferably 1/2 to 1 hour before breakfast ; I have experienced stomach pain every time.  The stomach pain has progressed to problems with diarrhea.   I am wondering if anyone else has experienced stomach issues/irritability when taking this medication?  The change seems to have occurred when they switched to the small purple pill with M on one side and L 6 on the other.  When I was taking a round white pill these problems never occurred."