Inclusion Criteria:  Diagnosed with congenital malformations or diseases requiring intestinal surgery leading to short bowel syndrome. or Diagnosed with conditions and diseases leading to intestinal failure e.g pseudo obstruction.  and  - Treated with parenteral nutrition for >3 months  Exclusion Criteria:  Patients in need of temporary parenteral nutrition intervention due to illness, e.g. infections. Patients with temporary malfunctioning gut due to advanced medical treatment, for example cancer treatment or transplantation