Use of N-methyl-N - [(1S) -1-phenyl-2 - ((3S) -3-hydroxypyrrolidin-1-yl) ethyl] -2,2-diphenylacetamide and / or a physiologically compatible salt of the same to prepare a medicine for the treatment of Irritable Bowel Sydrome (IBS) or Irritable bowel syndrome.Utilización de la N-metil-N-[(1S)-1-fenil-2-((3S)-3-hidroxipirrolidin-1-il)etil]-2,2-difenilacetamida y/o de una sal fisiológicamente compatible de la misma para preparar un medicamento para el tratamiento de Irritable Bowel Sydrome (IBS) o Síndrome del colon irritable.