Editing Large intestine (section)

==Other animals==
The large intestine is truly distinct only in [[tetrapod]]s, in which it is almost always separated from the small intestine by an [[ileocaecal valve]]. In most vertebrates, however, it is a relatively short structure running directly to the anus, although noticeably wider than the small intestine. Although the caecum is present in most [[amniote]]s, only in mammals does the remainder of the large intestine develop into a true colon.<ref name="VertebrateBody">{{cite book | title=The Vertebrate Body | publisher=Holt-Saunders International | author=Romer, Alfred Sherwood | author2=Parsons, Thomas S. | year=1977 | location=Philadelphia, PA | pages=351–354 | isbn=978-0-03-910284-5}}</ref>

In some small mammals, the colon is straight, as it is in other tetrapods, but, in the majority of mammalian species, it is divided into ascending and descending portions; a distinct transverse colon is typically present only in [[primates]]. However, the taeniae coli and accompanying haustra are not found in either [[carnivora]]ns or [[ruminant]]s. The rectum of mammals (other than [[monotreme]]s) is derived from the [[cloaca]] of other vertebrates, and is, therefore, not truly [[homology (biology)|homologous]] with the "rectum" found in these species.<ref name="VertebrateBody" />

In some fish, there is no true large intestine, but simply a short rectum connecting the end of the digestive part of the gut to the cloaca. In [[shark]]s, this includes a ''rectal gland'' that secretes salt to help the animal maintain [[osmosis|osmotic]] balance with the seawater. The gland somewhat resembles a caecum in structure but is not a homologous structure.<ref name="VertebrateBody" />