Pre-operative stool analysis for intestinal parasites and fecal occult blood in patients with acute appendicitis.

BACKGROUND: Etiology of acute appendicitis (AA) rarely involves parasitic infections of gastrointestinal (GI) tract. Preoperative diagnosis of parasitic infections in appendix remains difficult, although parasites can sometimes be observed inside the lumen during histopathological examination. The aim of the present study was to prospectively screen prevalence and species of intestinal parasites and adherence of fecal occult blood (FOB) in patients admitted to emergency department (ED) with clinical symptoms of AA who underwent appendectomy.

METHODS: Demographic and stool analysis data of a total of 136 patients (≥13 years old) who underwent appendectomy between July 2009 and December 2014 were prospectively assessed, and histopathological data of all patients were retrospectively assessed.

RESULTS: In histopathological examination after appendectomy, of 136 patients, 75.5% (n=103) had AA, 11.1% (n=15) had perforated appendicitis (PA), and 13.2% (n=18) had a negative appendicitis (normal appendix, NA). Pre-operative stool analysis revealed that 25% (n=34) had intestinal parasites and 14.7% (n=20) of patients had positive fecal occult blood test (FOBT). Those with positive FOBT represented 9.7% (n=10) of 103 AA patients, 53.3% (n=8) of 15 PA patients, and 11.1% (n=2) of 18 NA patients; this was statistically more significant for PA than other groups (p<0.001).

CONCLUSION: Presence of intestinal parasites in stool might not be associated with appendicitis, but it can occasionally lead to pathological findings of appendicitis. A positive FOBT may be a predictor for PA.