A 34-year-old premenopausal woman presents with fatigue. Hb is 88 g/L, MCV 70 fL and ferritin 6 µg/L. She reports heavy menstrual bleeding but no gastrointestinal symptoms. What is the most appropriate initial investigation strategy?ANo further investigation and treat with oral ironBUpper and lower gastrointestinal endoscopy urgentlyCPelvic examination and investigation for gynaecological causes plus coeliac serologyDBone marrow biopsyECT scan of abdomen and pelvisCheck my answer