Mucous fistula

​Mucous fistulas​ are a surgically-formed connection between bypassed colon and the skin surface. It is a type of colostomy, but instead of letting ingested contents pass out of the body, a mucous fistula allows release of colonic secretions, mucus, and gas so that they do not build up over time.

The mucous fistula empties into a bag. If a patient has a loop colostomy, then the stoma that enters into the downstream colon is essentially the mucous fistula, although it is not usually termed as such since the term mucous fistula is usually used for a separate stoma and bag.

An alternative to a mucous fistula is a Hartmann pouch. With a Hartmann pouch, the bypassed downstream colon is not externalized, as with a mucous fistula, but the end is stapled off and a blind end is formed. Sometimes the amount of colon that needs to be resected during surgery does not leave enough downstream colon to permit externalization, and a Hartmann pouch is necessary.

Terminology

"Mucous" is the adjectival form of the noun "mucus". Therefore when people write "mucus fistula", they should really say "mucous fistula".