Banana bag

A banana bag is a bag of IV fluids containing multivitamins. The bags typically contain multivitamins, thiamine and folic acid, sometimes magnesium sulfate, and are usually used to replenish nutritional deficiencies or correct a chemical imbalance in the human body. Most often they are used for alcoholics who need thiamine to prevent Wernicke-Korsakoff syndrome.

Multivitamin solutions as found in banana bags usually have to be administered within 24 hours of being mixed because the solution is unstable once mixed, and the benefits of the solution after that time period are far less predictable.

Multivitamins are yellow in color, which is what makes the fluid yellow, hence the term "banana bag". Banana bags are also known as "rally packs".