Metformin and digestive disorders

Diabetes Metab. 2011 Apr;37(2):90-6. doi: 10.1016/j.diabet.2010.11.002. Epub 2011 Jan 13.


Digestive disorders (diarrhoea, vomiting) represent the most common metformin side-effects (around 30%) with this first-line drug treatment for type 2 diabetes. In healthy individuals, metformin affects glucose, vitamin B12 and the digestive uptake of bile salts. In the colon, it acts locally by modifying glucose cell metabolism. Different pathophysiological hypotheses have been proposed to explain the metformin-induced diarrhoea and vomiting, which can sometimes cause the patient to stop an effective treatment. These theories include stimulation of intestinal secretion of serotonin, changes in incretin and glucose metabolism, and bile-salt malabsorption. However, none of these hypotheses can be considered an adequate pathophysiological explanation of metformin digestive side-effects. In addition, there is a lack of experimental data to explain these highly patient-dependent adverse effects.

Publication types

  • Review

MeSH terms

  • Bile Acids and Salts / metabolism
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diarrhea / chemically induced
  • Digestive System Diseases / chemically induced*
  • Digestive System Diseases / epidemiology
  • Glucose / metabolism
  • Humans
  • Intestinal Mucosa / metabolism
  • Intestines / drug effects
  • Metformin / adverse effects*
  • Metformin / pharmacokinetics
  • Serotonin / metabolism
  • Vomiting / chemically induced


  • Bile Acids and Salts
  • Serotonin
  • Metformin
  • Glucose