I just got my biopsy results back for my endoscopy. The two things noted were a gastric mucosal abnormality characterized by erythema in the lower third of my esophagus, and patchy mildly erythematous mucous (with no bleeding) in my gastric antrum. Both areas were biopsied and were apparently normal. If both were the result of crohn's would the biopsy have detected it? Are false negatives possible?