The gastrointestinal (GI) tract, also known as the digestive tract or the gut, is a system of organs primarily responsible for breaking down food, absorbing all the nutrients in the food we eat and getting rid of the waste.

Digestion and absorption of nutrients take place in the intestines. When a section of the GI tract is affected by disease, nutrients are not well digested or absorbed resulting in malabsorption and eventually nutrient deficiencies.