The columnar absorptive cells are tall, and as their name implies, have highly refined internal architecture which suits them for the purpose of water and electrolyte absorption. The goblet cells, on the other hand, are primarily perfected as mucin producing elements. There are at least a dozen and a half or more different types of enteroendocrine cells, which secrete (discharge) hormone-like peptides into the adjacent lamina propria and into the lumen of the bowel. These peptides have a variety of functions important to digestion and the motility or propulsive action of the colon.

The lamina propria is a mesh of tissue, primarily containing collagen, which is a connective type of tissue and occupies the space between crypts in the epithelium and the muscularis mucosa. Interestingly, it also contains lymphocytes and other cells of the immune system (called mast cells, plasma cells, macrophages, eosinophils and fibroblasts). The exact role and function of these cells here is not clear. Blood and lymph vessels, as well as nerve fibers, are found here.

The thin muscularis mucosa is situated at the base of the lamina propria and is spread like a sheet of fine filo dough.