<<Disclaimer: Verify this information before applying it to your situation.>>
 
The discovery of helicobacter pylori revolutionalized the way we think about
peptic ulcers.  I is a very common infection of the stomach and can stay there
for ever. It infects about 10% of the population being much more common in the
3rd world and in the elderly.  People have studied the rate of infection in CD
patients and it seems to be the same as the general population. Of course if yu
have both It can both confuse the doctor and worsen the abdominal pain and
indigestion symptoms. As far as i know the blood test for H pylori is not
interfered with by the presence of CD. The breath test, which will shortly be
available as a test in the US, is an excelllent test for infection.  The blood
test reflects infection in the last 6 months or so, and takes a while to become
negative when the bug has been eradicated.
Not medical advice
Joe Murray
Univ of Iowa