30th April 2024

A 25-year-old female presents with a six-month history of recurrent abdominal pain, bloody diarrhoea, and unintended weight loss.

A 25-year-old female presents with a six-month history of recurrent abdominal pain, bloody diarrhoea, and unintended weight loss. She reports urgency and tenesmus. Her symptoms are associated with fatigue and occasional low-grade fever. She denies recent travel, sick contacts, or use of nonsteroidal anti-inflammatory drugs. She has no family history of gastrointestinal diseases. Her physical examination reveals mild lower abdominal tenderness without rebound or guarding.

Which investigation is most likely to confirm the diagnosis?