Cloaca is not only the Latin for sewer but it is also the name of a machine/piece of art orginally shown at the MuHKA, Antwerp in 2000 (a new and improved version was later exhibitioned at the New York New Musuem of Contempory Art in 2001/2). Wim Delvoye developed Cloaca, costing $200,000 (or £128,000) after close consultation with scientists at the University of Antwerp.

Consisting (basically) of six jars, a waste disposal unit, electrical pumps, many feet of plastic tubing and a bit of computer wizardry arranged on a row of stainless steel tables, Cloaca is designed to closely mimic the human digestive system. It "consumes" two meals and 2.5 litres of water a day and (22 hours after a meal) excretes waste - which tests have shown has the same chemical composition as human faeces.

The machine's "products" are signed and sold for around $1,000 each - or you can buy your own (unsigned) turd on the internet from or

Food is placed in the mouth (a plastic funnel) and "chewed" by a modified waste disposal unit. It is mixed with saliva and enzymes, such as those found in the human mouth (an example being salivary amylase) which start to break the food down. It is shaped into a soft lump or "bolus" by the tongue and swallowed by an electric motor, forcing the bolus from the funnel into a tube representing the oesophagus.

The oesophagus is about 24cm long, food is pushed along by peristalsis (the process by which muscles in the oesophagus contract in waves, pushing the bolus along). In Cloaca, peristalsis in the rubber tubes is controlled by an electric motor.

Jar One - The Stomach
At first, the bolus is stored in the upper part of the stomach, after which muscle contractions mix the food and liquids with digestive juices (strong hydrochloric acid between pH1 and 2) to break it down. The resulting creamy substance (called chyme) is then pushed by peristalsis into the duodenum.

Jars Two and Three - The Small Intestine
The duodenum is the upper part of the small intestine and is about 25 cm long. Here the chyme is broken down further by enzymes and other secretions, in particular pancreatin from the pancreas (jar two) and bile from the liver (jar three).

The jejunum and the ileum make up the rest of the 6.5 metre long small intestine. They are covered in small bumps called villi, who's main purpose is to absorb nutrients. They are not represented in the exhibit as the nutrients and liquid waste are drained from Cloaca at a later stage.

Jars Four, Five and Six - The Large Intestine
Here the waste is formed and stored in a hollow tube about 1.5 metres long. The first part is the caecum, a poorly developed part near to a human's appendix. The main part is the colon (jars four and five), where the absorbtion of nutrients continues through the colon walls. By this stage most of what is left is either fibre or old cells shed from the mucosa. The colon is lined with a layer of moist mucas cells to lubricate waste as it moves (once again) by peristalsis. Glands in the colon's folds extract the remaining liquid before the waste is finally stored in the rectum (jar six).

In Cloaca faeces are passed throug a separator to drain off excess liquid before being ejected onto a conveyor belt; unlike the human anus, where faeces are passed into the anal canal before being expelled via a spincter.

Sources :
An article in Focus magazine (issue 122, January 2003)