 [ Symptoms ] i have taken metformin for my diabetes for two years i now have loose stool bloating and gas is this a side effect [ Disease ] this a great question that you can always ask your pharmacist yes these are common side effects from the medication it is very important that you drink a lot of fluids so you do not become dehydrated are you taking the medication with food this may help alleviate the gas and bloating i would also recommend mentioning this to your health care provider on your next visit they may adjust the dose of your medication