Detailed analysis of the intraoperative picture in 534 patients enabled the authors to develop the method for decimeter wave therapy (DWT) and introduce it into the combined treatment of the children presenting with destructive appendicitis after they underwent laparoscopic appendectomy. The effectiveness of the proposed differential approach to physiotherapy was based on the results of a comparative study of the patients’ conditions during the postoperative period with the use of DWT and without it. The study has demonstrated the advantages of DWT therapy given during postoperative period after the surgical treatment of destructive appendicitis in the children. It was found that the prescription of DWT therapy to the patients with appendicular peritonitis starting from the first day after the surgical intervention reduces the frequency of syndrome of systemic inflammatory reaction (SSIR) and intestinal insufficiency syndrome (IIS). Moreover, DWT was shown to accelerate the reversal of the latter syndrome. Its duration in 48% of the patients decreased down to 1.8 ± 1.2 days in comparison with 2.3 ± 1.3 days in 58.5% of the patients given the combined treatment without DWT. Syndrome of systemic inflammatory reaction was documented in 43.0% and 55.7% of the patients treated with the use of DWT and without it respectively, with its duration being 2.6 ± 1.6 and 4.9 ± 1.8 days (p < 0.05). In addition, the rapid elimination of the local inflammatory process under the action of DWT therapy was confirmed by the results of the tomographic examination of the anterior abdominal wall in the right ileal region. The patients treated with the use of DWT therapy experienced a two-fold drop in the absolute body temperature and temperature gradient within 5 days of the postoperative period.