CXCL8 and irritable bowel syndrome: In this way, the polymorphisms of the 5-HTR3 receptor, subunit A, subunit C-42 C>T and 5-HTR2 receptor subunit A, -1438(G/A) and 102 T/C, extensively reported as implicated in IBS predisposition and often associated with bloating, intense pain, and increased anxiety in IBS patients, will be correlated with presence of IL-8 ATCC haplotypes (at positions −251, +396, +781, and +1633) and IL 10 ACC haplotypes (at positions −1082, −819, and −592) in IBS patients.