December 2018 Question 2

A 26-year-old woman presents for an evaluation of an 8-month history of intermittent abdominal pain, which is associated with diarrhea. Her pain improves with bowel movements. She denies weight loss, GI bleeding, or nocturnal symptoms. There is no family history of IBD or celiac disease. Physical examination is normal. Thyroid function testing, C-reactive protein, celiac serology, stool studies for infectious pathogens, stool calprotectin, and colonoscopy with biopsies are all negative.