The role of colonoscopy in the diagnosis of appendicitis in patients with atypical presentations

Background: Acute appendicitis is one of the most common causes of acute abdomen. Despite recent advances in radiologic imaging, the diagnosis of acute appendicitis may be difficult on occasion. The aims of this study were to describe the colonoscopic features of appendicitis and to determine whether colonoscopy can be used as an adjunct for the diagnosis of appendicitis in patients with atypical presentations. Methods: The colonoscopic findings in 21 patients (14 men, 7 women; average age 55 years) with a colonoscopic or histopathologic diagnosis of appendicitis were analyzed retrospectively. Colonoscopy was performed because diagnoses suggested by CT were other than acute appendicitis (11 patients), and/or the presenting clinical features were atypical for acute appendicitis with the duration of symptoms being 10 days or longer (17 patients). Results: The colonoscopic diagnosis was acute appendicitis for all 21 patients. Seventeen underwent appendectomy, the diagnosis being verified in all cases. Of the 4 patients whose symptoms improved without appendectomy, 3 were considered to have acute appendicitis because pus was seen to drain from the appendiceal orifice at colonoscopy. A definite diagnosis could not be made in the remaining 1 patient. Therefore, the diagnosis of appendicitis was considered confirmed in 20 of 21 patients. Colonoscopic findings in these 20 patients included hyperemia (15) and bulging (18) at the appendiceal orifice area with surrounding mucosal edema (19), and drainage of pus from the appendiceal orifice (7). Conclusion: Colonoscopy may be useful in the diagnosis of appendicitis when the clinical presentation is atypical for appendicitis and/or imaging studies are nondiagnostic.