− | The most common condition causing simple obstruction of the small intestinal lumen.<ref>Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''', ''Merial''.</ref> | + | The most common condition causing simple obstruction of the small intestinal lumen.<ref name="Merck">Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''', ''Merial''.</ref> |