Interestingly, postinfectious IBS (PI-IBS, a subtype which is a consequence of past history or history of non-recognized bacterial, viral, or parasite GI infections) is believed to be associated with inflammation and mucosal damage rather than sporadic IBS, and according to Sadeghi et al., its characteristic features are increased macrophages, T lymphocytes, and serum IL-6 [27]. This evidence concerns the gene IL6 and irritable bowel syndrome.