Bilious fever was a medical diagnosis often used for any fever that exhibited the symptom of nausea or vomiting in addition to an increase in internal body temperature and strong diarrhea. "Bilious" means the condition was thought to arise from disorders of bile, the two types of which were two of the Four Humours of traditional Galenic medicine in 200 A.D.
The term is obsolete and no longer used, but was used by medical practitioners in the 18th and 19th centuries, often cited as a cause on death certificates. President Lincoln's son Willie was said to have died from bilious fever. Modern diagnoses for the same symptoms would include a wide range of conditions and infections.
- George W. Givens, "Language of the Mormon Pioneers", Bonneville Books (2003), p 19.