Diarrhea after using metformin is mostly due to the adverse reaction of the drug, oral flavonoids are generally not recommended for treatment, it is recommended to consult your doctor for treatment options in a timely manner. Metformin is a biguanide class of hypoglycemic drugs, mainly by increasing the utilization of glucose in peripheral tissues, inhibit the production of hepatic glycogen and reduce blood glucose levels, in the clinic can be used in patients whose blood sugar does not reach the standard through diet and exercise therapy, and can be used in combination with other hypoglycemic drugs to reduce blood glucose. Note that patients who are allergic to metformin can not take it, patients with severe alcoholism, patients who lack vitamin B12 and folic acid can not take it orally, patients with diabetic ketoacidosis, severe renal impairment can not be used. In clinical oral metformin the most common adverse reactions for digestive symptoms, some patients may have diarrhea, this happens it is recommended to first start with a small dose, observe any significant adverse reactions, gradually increase the dose. Adjust the oral time of the drug, change the fasting before meals to take during or after meals, to reduce the stimulation of the intestinal tract. After the above treatment, the patient may have a certain degree of tolerance to the drug, diarrhea is more serious can choose montelukast to carry out the treatment, relatively speaking, montelukast diarrhea effect is better, and no adverse drug reactions, if necessary, can be replaced with other hypoglycemic drugs. In the clinical oral metformin, it is recommended to consult the endocrinology department of the regular hospital.