For CF patients, gastrointestinal (GI) complications may involve the pancreas, small intestine, liver, and large intestine. The main function of the GI tract is to digest food and remove waste products. There are many organs involved:

Mouth	Glands secrete digestive enzymes that begin digestion.
Esophagus	Transports food from the mouth to the stomach.
Stomach	Secretes digestive enzymes and mechanically compresses the food.
Pancreas	Secretes enzymes for digestion and hormones regulating metabolism.
Liver	Filters the blood, removing toxins.
Gallbladder	Releases bile that aids in digestion.
Small intestine	Absorbs most of the nutrients from the digestion of food.
Large intestine	Reabsorbs water and forms feces.