I was diagnosed as hypothyroid in Dec 2014 and put on 50mg. I had my thyroxine increased to 75 mg in February of this year and told to take it on an empty stomach in the morning and wait 30 min before breakfast by the pharmacist. I also take omaprazole before food in the morning, so was taking them together. I then got diarrhea pretty badly and tried to figure out what was causing it. I took Immodium quite a lot. I have had stool test and blood test come back negative and now my GP wants me to have a colonoscopy. I still believe that the medication started it all off. The diarrhea seems to have gone away in the last week which makes it really weird. Does anyone have a handle on this? My GP is adamant that it's not the thyroxine.