The mucosa is the innermost layer of the colon. Major components of the mucosa include a single layer of epithelial cells, a layer of connective tissue (the lamina propria), and a thin muscle layer (the lamina muscularis mucosae).
The mucosa is lined with goblet cells, which are glands that secrete mucus to help move material through the colon. When you get a colonoscopy or sigmoidoscopy, it's your mucosa that the doctor's inspecting for polyps.
