A 36-year-old woman presents with persistent abdominal pain and constipation (Table 1). Upon inquiry, she states that she has experienced abdominal and bowel-related symptoms since she was in college. Her abdominal symptoms include intermittent cramps that typically occur in the left lower quadrant, nearly constant bloating that worsens during menstrual periods, and frequent episodes of constipation. She reports that her hard, small stools are associated with a feeling of incomplete emptying. She typically moves her bowels every other day. She denies seeing blood in her stool, fever, or unexplained weight loss, and she is not awakened at night by her symptoms. She exercises most days and has a normal body mass index (BMI). Her previous medical history includes an appendectomy at the age of 16 years. She reports no prior pregnancies (G0P0). Her family history is notable for breast and lung cancer, but no colorectal or gastric cancer.