Gastroenterology and Hepatologycommon
A 28-year-old woman presents with eight months of crampy lower abdominal pain that eases after opening her bowels, together with bloating and a bowel habit alternating between hard pellets and loose stools. She has never noticed blood in the stool, her weight is stable, and the symptoms never wake her at night. There is no family history of bowel cancer or inflammatory bowel disease. Physical examination, full blood count and C-reactive protein are all normal. Which one of the following investigations is most appropriate before confirming the diagnosis?