Co-occurrence of IBS and symptoms of anxiety or depression, among Norwegian twins, is influenced by both heredity and intrauterine growth
1 Medical Department, Vestfold Hospital Trust, Tønsberg, 3103, Norway
2 Norwegian University of Life Sciences, Ã…s, 1432, Norway
3 EpiGen-Institute, Faculty Division Akershus University Hospital, University of Oslo, Oslo, Norway
4 Division of Epidemiology, The Norwegian Institute of Public Health, Oslo, Norway