Chyle (from Greek χυλός (chylos) 'juice'[1]) is a milky bodily fluid consisting of lymph and emulsified fats, or free fatty acids (FFAs).

It is formed in the small intestine during digestion of fatty foods, and taken up by lymph vessels specifically known as lacteals.

A chyle fistula occurs when defect(s) of lymphatic vessel(s) result in leakage of lymphatic fluid, typically accumulating in the thoracic (pleural) or abdominal (peritoneal) cavities,[2] leading to a chylous pleural effusion (chylothorax) or chylous ascites, respectively.

Due to the extreme friability of the lymphatic vessels, direct repair of defects is impractical.

Decreased production of lymphatic fluid may be accomplished by dietary restriction (or complete replacement of oral intake with total parenteral nutrition), as well as by the medications octreotide (a synthetic analogue of the hormone somatostatin)[3] and orlistat (a lipase inhibitor that decreases absorption of dietary fats).