Review Question - QID 210893

A 33-year-old man presents to his primary care physician for fatigue, weight loss of 25 pounds, and pruritus. He has a medical history of multiple admissions for abdominal pain and bloody diarrhea as well as several episodes of ascending cholangitis which were treated. He has intermittently been on an immunomodulator for his underlying bowel condition with good control of his symptoms. He is currently a member of Alcoholics Anonymous and has not drank alcohol in over 1 year. His temperature is 98.2°F (36.8°C), blood pressure is 124/75 mmHg, pulse is 100/min, respirations are 13/min, and oxygen saturation is 99% on room air. Urinalysis is notable only for a dark urine sample with no red blood cells. A rectal exam reveals pale stool and grossly visible blood. Physical exam is otherwise notable for pruritis, jaundice, and scleral icterus. Which of the following is the most likely underlying diagnosis?