{'fraction_non_alphanumeric': 0.02551203736974488, 'fraction_numerical': 0.04743083003952569, 'mean_word_length': 4.961456102783726, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 2, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Rifaximin in the Treatment of Patients With Diarrhea-Predominant Irritable Bowel Syndrome.

2 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 Dear Editors: We read with interest the article by Lembo et al evaluating the safety and efficacy of repeat treatment with rifaximin in patients with diarrhea-predominant irritable bowel syndrome (IBS-D). The authors found that repeat rifaximin treatment was efficacious and well-tolerated in a phase III study of patients with relapsing symptoms of IBS-D. Because their findings are important to both current practice and future research, several questions deserve attention. First, although repeat treatments of rifaximin had significant improvement in symptoms of IBS over placebo, it is notable that only 38.1% patients had a response to treatment with a small incremental benefit compared with 31.5% improvement in placebo group. Some studies have concluded that there are beneficial effects with rifaximin for IBS-D, but the results have been questioned because of patient selection, the choice of endpoint, the optimal dose of rifaximin, and the statistical analysis. Although the therapeutic effect persists after the 2-week treatment period, there is some loss of efficacy, as compared with placebo, with respect to certain symptoms toward the end of the treatment-free observation (10-week and 4-week follow-up periods). At present, there is no study about comparison of the efficacy of rifaximin and other medications, such as antispasmodics, alosetron, antidepressants, probiotics, fiber, and peppermint oil for the treatment of IBS-D. Although rifaximin was safe and well-tolerated in this study, it is unknown whether long-term use could lead to antibiotic resistance or antibiotic-induced diarrhea or Clostridium difficile colitis. At the same time, the similar structural relationship between rifaximin and rifampin leads to rifampin resistance. At present, the emergence of rifampin-resistant skin staphylococci after intake of rifaximin has been reported. However, the development of these resistances was not investigated in this study. Second, IBS is a heterogeneous bowel disease with multiple pathophysiological mechanisms. The mechanism underlying the beneficial effect of rifaximin for IBS-D is a matter of controversy. Initial studies of rifaximin for the treatment of IBS-D patients were based on the hypothesis that a large proportion of IBS-D patients had small intestinal bacterial overgrowth (SIBO), a disorder characterized by the presence of abnormally high numbers of bacteria in the small intestine. These studies also reported the presence of SIBO in 80% of IBS-D patients, on the basis