How to build a large intestine model

Updated April 17, 2017

A science fair project that wows the judges is what every student wants. A realistic looking large intestine model is a perfect choice for originality and creativity in a science fair project. Having extensive knowledge about what the large intestine is designed to do in relation to the digestive system of the human body, along with a realistic looking gut laid out on the table, will impress the judges.

Soak the hog casing for 24 hours. This allows for the sausage casing to become soft and pliable.

Cover the sink with the garbage bag and put on the gloves.

Mix red food dye into the spaghetti noodles. Add as much colouring as desired. It is best to wet the noodles with cold water to make sure they slide and don't stick.

Using the kitchen knife, cut 6 feet of casing. Tie a knot into one end.

Wrap the open end of the casing over an end of the PVC pipe. Make sure enough of the casing is over the pipe so it will not slip off during stuffing. At least 4 inches should work.

Fill the casing with the wet, red spaghetti. The casing will only stretch so far. The 38 to 42mm casing will expand to a 1 to 1 1/2 inch wide intestine.

Place the intestine so that it looks like it's piled upon itself. This makes it look like real intestines.


If the spaghetti is not easily sliding down the casing, pour water in at the same time as adding the spaghetti noodles. This will help the noodles to slide down. Drain the water with each handful of spaghetti. The large intestine in an adult is 5 feet long. It is known as the large intestine for its thickness, 1 1/2 inches, rather than its length.


The food dye will permanently stain skin and sinks. Always protect the equipment used with plastic covers such as gloves and garbage bags.

Things You'll Need

  • Clear hog casing, 38 to 42mm
  • Large bucket
  • Cooked spaghetti noodles
  • Vegetable oil
  • Red food dye
  • Kitchen knife
  • 6-inch PVC pipe
  • Rubber gloves
  • Garbage bag
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About the Author

Amy Lea has been writing since 1993. Her work has been published on numerous websites. She specializes in writing how-to and education articles. Lea received an Associate of Arts in teacher education from St. Louis Community College.