I think these anomalies are all too frequent with IBD, which may explain why docs have a hard time diagnosing it, or are fast at writing it off as IBS. Think about it, they look at bloodwork with normal WBC, in a patient who isn't displaying a fever at the time, but complains of aches N diarhea... no indicators of inflamatory bowel disease. As to why... Good question. But the fact that this disease is caused by/responsible for a 'wacky' immune response... maybe the extent to which it is able to fool the body does some pretty big pendulum swings at times. Food for thought... Think many a stardard GP/family medicine physician, or emergency room staff, COULD be fooled by this pretty darned easy. Most GI's just learned from experience that these tests or markers don't always tell the whole story (And, no pun intended... else I wouldn't have spelled whole with a W, right?)