Celiac Disease is an autoimmune disorder where exposure to wheat protein(gluten) causes an inflammatory response in the small bowel. This can cause symptoms similar to IBS. Celiac Disease can cause all sorts of digestive problems. You can get tested for it via a blood test or during a colonoscopy via biopsy. The blood test alone may not be a definitive result, even if it comes back negative. So if you’re planning on getting a colonoscopy ask your gastric doctor if they can check for Celiac.
Some people may not have Celiac disease specifically, but just have an allergy to wheat. You can become allergic to all sorts of foods & it can happen practically at anytime.
A wheat/gluten free diet is where one abstains from eating ANY wheat or gluten based product. This is an all or nothing proposition and is a MAJOR lifestyle change as so much stuff out there contains wheat or gluten in it. If you are going to try this diet out, you really need to be committed and make sure that the others in your household are committed to your success as well.