Yellow stool is usually caused by the body's inability digest fat because of malabsorption, states MedicineNet. This can be caused by celiac disease, cystic fibrosis or the inability of the pancreas to manufacture the correct digestive enzymes.
Celiac disease is the name given to an inflammation of the small intestine as a result of being exposed to gluten, states MedicineNet. The disease usually causes abdominal discomfort, such as bloating, nausea or loose bowel movements. Because of the inflammation, the small intestine may lose its ability to absorb nutrients, which may lead to yellow stool. It is thought that the disease has a genetic or familial component, meaning one is more likely to develop the disease if someone in the family already has it.
Cystic fibrosis is an inherited condition that causes severe damage to the lungs and digestive system, states Mayo Clinic. The disease primarily affects cells in the body responsible for producing mucus, digestive juices and sweat. In people with cystic fibrosis, the aforementioned fluids become very thick, and they can plug passageways in the lungs and pancreas. Although there is no cure for cystic fibrosis, there are treatments available that ease symptoms and reduce complications associated with the disease. In fact, many people with the disease have a better quality of life than in previous decades, and they may survive anywhere between 40 and 50 years with it.