Q. A 30-year-old woman presents to your clinic with a three-month history of abdominal pain, diarrhea, and unintentional weight loss. She reports that her bowel movements occur four to six times daily, often with a sense of urgency, and sometimes contain blood. Recently, she has also experienced fecal matter passing through her vagina. She denies any history of travel or ingestion of uncooked foods. She has no similar complaints in her family. Her temperature is 99°F (37.2°C), pulse is 92 beats per minute, blood pressure is 110/70 mmHg, and respiratory rate is 14 per minute. On physical examination, she looks lean and her abdomen is tender to palpation in the lower right quadrant without rebound or guarding. Considering her clinical presentation, which of the following diagnoses is most likely?