The effect on the colon caused by malnutrition due to gastric restriction surgeries in the stomach has not yet been studied. The objective of the present study is to evaluate and quantify the acid and neutral mucin contents, as well as the number of goblet cells in the colon and their respective crypts, of rats submitted to gastric restriction for 10 days. We also intend to correlate any changes found with acute weight loss, with the aim of contributing to the effectiveness and safety of this therapy that has been increasing worldwide.