A CBC counts your red blood cells (checking for anemia), your platelets (blood cells that help your blood clot) and white blood cells (that fight infections). An internal infection would typically increase your white blood cell count, but of course there can be exceptions depending on the site of infection and the infectious agent. Is there a particular body site/bug you had in mind?
CBC should be very accurate but like said only shows the count and percentage of all blood cells. For checking an infection there are microbiological tests and even then checking for almost each bacteria (or type of bacteria) or virus has to be done separately - for one type one test. If tuberculosis would be suspected for example, the special test for tuberculosis would have to be done.
On the other hand it is less likely to have an infection if the CBC is normal. But samples can be taken from stomach or urine or sputum also.
typically a bad gall bladder can only be diagnosed with a HIDA scan, or a less reliable way, an ultra sound for stones. ususally a gallbladder stops functioning properly, or there are stones, but i am not familiar with a gall bladder infection. an appendix may become infected and is also on the right side, but a CBC would show an elevated WBC in that case.
check out the digestive disorder board for more info on gall bladder disease/problems. there are some suppliments you can take to help and possibly avaoid an operation.
hope you feel better, BTW my husband is a far scape nut too.
Married October 02
DS Caden Grey June 03
DS Morgan Keenan March 05
C-Section Aug 1st 08 with baby BOY #3