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Mesalazine in the Treatment of Symptomatic Uncomplicated Diverticular Disease.

To the Editor: We read with interest the article by Picchio et al1 evaluating the effectiveness of mesalazine in improving symptoms (abdominal pain) and in preventing diverticulitis occurrence in patients with symptomatic uncomplicated diverticular disease (SUDD). The authors found that mesalazine is effective in achieving symptom relief and primary prevention of diverticulitis in patients with SUDD. Because their findings are important to both current practice and future research, several questions deserve attention. First, our attention was focused on the long-term efficacy and safety of mesalazine on the chronic symptoms of SUDD, because the information of safety is important as mesalazine is an anti-inflammatory drug with known side effects. But all the included studies in this systematic review only used mesalazine for short periods or in cyclic administration. At the same time, the results of this study might have been affected by other concomitant therapies (probiotics, highfiber diet, etc.). There is recent evidence that the other concomitant therapies adversely affect the outcome of mesalazine for SUDD patients.2 And a recent meta-analysis has found no evidence to support a role for mesalazine in the prevention of recurrent diverticulitis on DD patients.3 Second, some studies have found that the important pathogenesis of the SUDD symptoms is alteration in the intestinal bacterial microecology, which contributes to maintaining a low-grade inflammation. But an antiinflammatory drug such as mesalazine may be effective only against the second phase of the pathogenetic process. Therefore, the target of the therapy should be the altered microflora, which may be reached by using probiotics or nonabsorbable antibiotics (such as rifaximin). Third, some studies have demonstrated that some symptoms of SUDD patients are similar to those seen in the irritable bowel syndrome.4 And there is evidence from large cohort studies that SUDD patients exhibit different and more specific abdominal pain patterns.5 The recent demonstration of abnormalities of both the enteric nervous system and of mucosal neuropeptide pattern in SUDD patients,6,7 suggests that the origin of symptoms may likely be due to other mechanisms than that related to low-grade inflammation of the mucosa. Therefore, we feel that there is a possibility that the present efforts based on decreasing low-grade mucosal inflammation in SUDD are aimed at a wrong target, there is still no firm documentation of such an efficacy of the present therapies in this setting. In conclusion, we believe that caution is necessary regarding the widespread use of mesalazine for SUDD. And more randomized prospective trials are needed to evaluate the long-term efficacy and safety of mesalazine on SUDD patients. At the same time, it is our belief that only with a better understanding of the pathophysiological mechanisms of SUDD; we will be able to focus on more precise therapeutic targets. Cong Dai, MD, PhD Min Jiang, MD Ming-jun Sun, MD Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang City, Liaoning Province, China