The long-term outcome after negative appendix operation.

We evaluated the long-term outcome of "negative appendix" (NA) by analysing the follow-up results of 76 patients identified from a group of 670 appendectomized patients. Randomly selected and histologically proven cases of true acute appendicitis (TA) matched for age and sex were identified to construct case control pairs. Special interest was focused on gender and age, by analysing the results separately in men and women in two age groups (15-39 years and > or = 40 years). The results showed that NA was most common in women aged 15-39 years (21% of appendectomized cases in this age group). At follow-up examination after a mean follow-up of 2.9 years two-thirds of patients were symptomfree. Women aged 15-39 years had significantly more complaints (P < 0.05) and findings (P < 0.05) than patients with TA. In women aged > or = 40 years no significant differences were detected, nor in either age groups in men. Lactose intolerance was the most common finding in symptomatic patients. In conclusion, patients with NA were mostly young women. At long-term follow-up the great majority of patients were symptomfree and appeared not to have developed any serious disease. Routine follow-up for patients with NA does not thus seem necessary.