How to differentiate IBD from acute infectious diarrhea?
The initial presentation of IBD can sometimes be difficult to distinguish from some forms of acute infectious diarrhea. IBD can be considered in patients with persistent bloody diarrhea (> 7 days) with a negative infectious workup and lack of response to empiric therapy. Suspicion for IBD is increased in patients with a history of recurrent or chronic gastrointestinal (GI) complaints, in patients 20 to 30 years of age, and in those with extraintestinal manifestations of IBD (aphthous ulcers, uveitis, arthralgias, erythema nodosum, pyoderma gangrenosum). Lower endoscopy is indicated to help distinguish between these diagnoses, although the endoscopic features between IBD and acute infectious diarrhea are quite similar in the early phases of each disease. Inflammatory markers such as erythrocyte sedimentation rate (ESR) are nonspecific for IBD, but are often markedly elevated.