Charlotte, a 14-year-old girl, presents with longstanding intermittent abdominal pain, bloating and watery diarrhoea.

She reports she has needed to open her bowels urgently after meals, several times a day, for as long as she can remember.

This has resulted in her avoiding eating socially and feeling she always needs to know where a toilet is.

Symptoms like these have been a problem for many years and have waxed and waned, on and off, with no clear precipitants or triggers throughout her life.