MSFinals-0709
A 21-year-old student presents to his General Practitioner with intermittent watery diarrhoea and lower colicky abdominal pain. He has experienced these symptoms for two years and during this time has lost over a stone in weight. Recently he has noticed a strange red rash on his shins. Past medical history includes a diagnosis of a fissure-in-ano three years ago.
What is the most likely diagnosis?