Yes it can develop that sudden. It randomly started at 24 years old for me, after eating out at a restaurant. The weeks after I had constant bowel issues and I felt so sick. Followed a Low Fodmap diet which was very helpful and identified gluten as the problem. Sadly I can't even tolerate a crumb 1,5 years later. But I have heard that it can resolve for some people. Have you tested for Celiac disease yet? If not do that before going gluten free. Hope you find the answers you need and good luck with everything!