Irritable bowel syndrome is one of the most frequent diseases of the gastrointestinal tract. Doctors working in different fields deal with this problem in their everyday practice. The frequency of this disorder is 10-20% in the adult population and it is a frequent cause of work absence. Thus, it is not only a general medical problem but also a social one. This syndrome is one of the most typical examples of psychosomatic disorders - somatic disorders conditioned or worsened by psychosocial factors. The process of disturbance development in this syndrome is complex and in most cases, to some degree, associated with depressive symptoms. It may be a result of conversion of anxiety into somatic symptoms. It is frequently a result of the so-called dissociative conversion - a transformation (conversion) of persistent anxiety symptoms into secondary somatic disturbances. The authors suggest two possible mechanisms connecting irritable bowel syndrome and depression. They also distinguish in a novel way several types of this syndrome basing on the accompanying psychopathological symptoms. The paper also suggests possible therapeutic approaches in all the presented sub-types of irritable bowel syndrome.