 Chronic constipation is a common condition with a heterogeneous pathophysiology and resulting clinical manifestations. Recent evidence in the literature and collected in our laboratory confirm that there are differences in the gut microbiota between healthy individuals and those with a variety of disorders e.g., inflammatory bowel disease, irritable bowel syndrome and obesity suggesting that the development of certain disorders may be determined by the composition of the gut microbiota. Existing evidence warrants further investigation of the role of the microbial ecology of the human gut in constipation and an exploration of modification of the gut microbiota as a means to treat constipation by its actions on the colonic metabolism of nutrient substrates to alter colonic transit and fluid fluxes. 