20th July 2020

A 41-year-old gentleman presented to his GP following 4 months of unresolved tiredness, weight loss and pruritus

A 41-year-old gentleman presented to his GP following 4 months of unresolved tiredness, weight loss and pruritus. He was previously diagnosed with ulcerative colitis and asthma when he was 32 and 16 years old respectively. Investigations were done which showed raised Alkaline Phosphatase (ALP) and raised Gamma-Glutamyl Transferase (GGT), a normal antibody test and Magnetic Resonance Cholangiopancreatography (MRCP) finding. Thus, a diagnosis of small duct Primary Sclerosing Cholangitis is suspected by his clinician. 

Which further investigation below would provide the best diagnostic value in confirming his diagnosis? Select ONE option only.