3. Celiac Disease
People who are allergic to gluten may experience stool that is runny and yellow. Some people have a minor allergy to gluten, while others have what is called celiac disease. When a person who has celiac disease eats gluten, which is a protein that is found in barley, rye, and wheat, the immune system will respond by starting to attack the tissues located in the small intestine. This response from the immune system causes the tissues to become damaged. When the tissues of the intestine are damaged, the ability to absorb nutrients by the intestines is compromised. Along with yellow stool, a person with celiac disease might also experience constipation, diarrhea, fatigue, depression, headaches, bloating, and nausea. If you are experiencing these symptoms, it is important to find the underlying cause. Your doctor will help you come up with a diet and a plan to help control this issue if it is the cause of your yellow stool.