Gluten intolerance is a condition in which the body cannot properly digest gluten, a protein found in wheat, barley and rye. Symptoms of gluten intolerance can vary from person to person, but may include diarrhea, constipation, bloating, gas, stomach pain, fatigue and joint pain. A Gluten Intolerance Symptoms Checklist can help you track your symptoms and identify potential triggers. This can help you work with your doctor to develop a treatment plan that works best for you.