What is the normal size of the common bile duct?
Various authors report different "normal" ranges for the
diameter of the common bile duct. The consensus is that most people
have a common bile duct diameter of around 5mm, +/- 1 mm. However,
there are reports were people with no hepatobilliary disease have a
"normal" common bile duct size up to 10 mm. Also, there is a
correlation between common bile duct diameter and age. Most
physicians would like to check things further if the common bile
duct diameter is greater than about 7 mm, particularly if there are
symptoms indicating hepatobilliary disease (abdominal pain with or
without jaundice, fever etc.). Finally, even "normal" common bile
duct sizes do not exclude the possibility of disease (such as
stones).