The intestinal mucosal epithelium has goblet cells which secrete mucus.

The secretion of brush border cells (of mucosa) and the goblet cells together form intestinal juice also known as succus entericus. This juice contains enzymes like disaccharidases, dipeptidases, lipases, nucleosidases, etc.

The mucus plus the bicarbonates from the pancreas protects the intestinal mucosa from acidic food entering from the stomach. They also provide an alkaline medium (pH 7.8) for enzymatic activities.