What coeliac disease can involve
Coeliac disease is an autoimmune condition, not an intolerance: gluten causes the immune system to damage the lining of the small bowel. A strict gluten-free diet is the whole of the treatment, which sounds simple until you are reading the back of a packet in a supermarket, or working out whether the chips were fried in the same oil.
What people rarely mention is the tail. A reaction can arrive hours later and last for days, so the meal and the consequence feel disconnected. Fatigue, brain fog, mouth ulcers and joint aches ride along with the gut symptoms. Written down in one place, the pattern between what you ate and how the next two days went stops being guesswork.