Question 2: How commonly do children with acute appendicitis present with diarrhea?

A 2011 retrospective study by Gendel and colleagues evaluated 1,848 children admitted to a pediatric surgical service over a five-year period.¹ Of these, 686 underwent appendectomy for suspected acute appendicitis. The negative appendectomy rate was 5 percent. Of the patients who demonstrated acute appendicitis, 9 percent had diarrhea. Another retrospective study by Choi and colleagues evaluated 712 pediatric patients with surgically confirmed acute appendicitis.² There was noted diarrhea in 10.7 percent of patients with confirmed acute appendicitis. Interestingly, in cases involving a delayed diagnosis of acute appendicitis, diarrhea was present in 18.1 percent of cases, suggesting that the presence of diarrhea may have falsely reassured clinicians at the time of initial evaluation.

A retrospective case control study by Lu and colleagues evaluated 114 pediatric cases with either acute appendicitis (n=32) or acute gastroenteritis (n=82).³ All the children had been admitted for abdominal pain evaluation, and data were analyzed according to their final diagnosis. The authors sought to better delineate clinical characteristics of these two diagnoses. Regarding diarrhea specifically, there was no clinically significant difference between the average number of days of diarrhea for either acute appendicitis (1.78 ± 2.11 days) or gastroenteritis (1.76 ± 1.47 days), suggesting that diarrhea should not dissuade the clinician from evaluating for acute appendicitis.

While acute appendicitis is much less common in children younger than 5 years of age, the clinical presentation in young patients with acute appendicitis is typically less straightforward.

A 10-year retrospective study by Pogorelic and colleagues evaluated 1,687 appendectomies at a single institution. Only 5.3 percent (90) of the cases were identified in children younger than 5 years of age.⁴ The authors also analyzed the data according to appendiceal perforation or nonperforation. In the 90 children younger than 5 years of age, 58 cases were perforated while 32 cases were nonperforated. Overall, 30 of 90 (33 percent) children under 5 years with acute appendicitis had diarrhea, and 29 of 30 cases with diarrhea were in the perforated appendicitis group. While acute appendicitis in children younger than 5 years is uncommon, diarrhea was not uncommon in these individuals. The present of diarrhea should therefore not influence the practitioner away from considering appendicitis in a pediatric patient with lower abdominal pain.

Conclusion

Overall, the literature suggests that diarrhea is present in approximately 10 percent of cases of acute appendicitis; its presence should not falsely reassure the clinician with higher suspicion of acute appendicitis. Additionally, while appendicitis is much less common in children younger than 5 years of age, diarrhea, in particular, appears to be relatively common in children in this age group with acute appendicitis.