An acute inflammation of the INTESTINAL MUCOSA that is characterized by the presence of pseudomembranes or plaques in the SMALL INTESTINE (pseudomembranous enteritis) and the LARGE INTESTINE (pseudomembranous colitis). It is commonly associated with antibiotic therapy and CLOSTRIDIUM DIFFICILE colonization. The disease is EFO_1001314 (pseudomembranous enterocolitis). Also known as: Enterocolitis, Pseudomembranous.