So this is what I found.....
The basic histological structure of the alimentary tract is similar throughout its length and comprises several layers. Beneath the surface epithelium (which varies in type from region to region) and its basement membrane, is a lamina propria, a loose fibrovascular connective tissue which in many filled with mononuclear inflammatory cells ready to deal with invading antigens, including plasma cells that make IgA that is transported into the gut lumen.