Study	Reason for exclusion
Anderson 1997	This study investigated the role of barium in the diagnosis of complete or partial small bowel obstruction, it did not use water soluble contrast. The study does not address the questions of this review.
Blackmon 2000	This study was excluded because it was a retrospective review
Chen 1998	This was a duplicate paper where patients were included in Chen 1999.
Choi 2002	In this study the authors treated patients conservatively for 48 hours and those who did not respond were randomised to either oral Gastrografin treatment or surgical intervention
Dunn 1984	This study included patients with small bowel obstruction which is not related to previous surgery, some patients had colonic cancer or caecal lesions. Barium as well as water soluble contrast were used .
Enochsson 2001	This was a retrospective study to evaluate the degree of small bowel obstruction, it used mixture of gastrografin and barium, the correlation with the need for surgery was not analysed.