I started on metformin SR 3 a day 18months ago. Initially this gave me constipation which I managed to correct with of lots bran, fruit and water. The problem of constipation has started again even though I still take bran fruit, water etc. My Dr has prescribed Lactulose which works as long as I use it every day. I do not want to continue using this on a daily basis. Do you think its time to ask my Dr about changing my medication? My HbA1c is just over 7, so I feel that Metformin is controlling my Diabetes.