Monoject syringes are used for several different medical procedures such as flushing foley catheters, ostomy irrigation, and delivering liquid oral medication. These needle-free syringes are made from sturdy transparent plastic. They also have markings printed on the outside to measure the correct amount of fluid that needs to be administered. Monoject syringes are available with a standard tip or a catheter tip. The catheter tip syringe is typically used when injecting fluid through medical tubing.