There are many people who live with a form of minor celiac disease without realizing it. Some who have a weak form of it may not notice it until their late 20's.
Typically, a person can see signs of celiac disease when they experience vomiting, uneasy bowel movements, constipation or diarrhea. But how would you know that isn't the cause of just eating some bad, possibly poisoned food? Fortunately, there is a surefire way to determine if it is celiac disease or not. If, after consuming bread (the most common edible item that has gluten) you get a lasting pain, such as mouth soreness or joint pain or skin rashes on top of the signs listed above, then you may very well have the disease.
The simple thing to do would be to have gluten-free meals everyday. With today's technology, you can simply go on the internet and research on what food would be recommended in a gluten-free diet. The more expensive approach would be to see a dietician.
Today, there are people who have a minor form of celiac disease. They can eat grains and cereal and won't feel anything more than a minor stomach ache later in the day. It would not come across their mind that the ache came from what they had for breakfast. In the case of someone experiencing this minor inconvenience, it is still okay to eat gluten food as long as the portions are controlled. It is also recommended to only eat those gluten foods only every so often. For more in depth information about celiac disease symptoms, prevention and treatment visit the link below.