Table 1. Histological key features of microscopic colitis: collagenous colitis and lymphocytic colitis.

Clinical groups	Morphology subgroups	Increased mononuclear inflammation of lamina propria	Thickness of collagenous band	Number of IELs
MC	CC	Moderately increased	>10 ìm	Normal/slightly increased
	LC	Moderately increased	Normal/slightly increased	>20 IELs/100 cells

MC, microscopic colitis; CC, collagenous colitis; LC, lymphocytic colitis; IELs, intraepithelial lymphocytes.