A 35-year-old woman presents with chronic diarrhoea and iron deficiency anaemia. Tissue transglutaminase IgA (tTG-IgA) is strongly positive, and total IgA level is normal. What is the most appropriate next step?AStart a strict gluten-free diet and arrange small bowel biopsy to confirmBReassure that this is likely irritable bowel syndromeCOrder anti-mitochondrial antibodiesDPerform colonoscopy onlyEDelay any intervention because tTG-IgA is non-specificCheck my answer