Efficiency of management of patients with irritable bowel syndrome with constipation and autoimmune thyroiditis with hypothyroidism using rifaximin

Background. Irritable bowel syndrome (IBS) is a common gastrointestinal sign of gut-brain axis disorder, which occurs with abdominal pain, bloating and abnormal bowel motility, and may be divided onto subtypes: with prevalence of constipation (IBS-C), diarrhea and mixed. Autoimmune thyroiditis (AIT) is the most prevalent endocrine disorder diagnosed in young patients, which can often coexist with IBS and influence its clinical course. Small intestinal bacterial overgrowth (SIBO) is usually registered in both disorders. SIBO treatment can improve the course of IBS. The purpose of the study is to assess the efficiency of additional use of rifaximin in treating patients with IBS-C and AIT with hypothyroidism. Materials and methods. It is a prospective single-centered study, which included 77 patients with IBS-C and AIT with hypothyroidism. All participants were divided into 2 groups: 46 people received clinical guideline IBS treatment (group I), and 31 patients took rifaximin additionally (group II). The intensiveness of gastrointestinal symptoms such as abdominal pain, bloating, nausea, vomiting, heartburn and epigastric pain was evaluated with the use of Likert 5-grade scale. The mental status was assessed with the Ukrainian version of Hospital Anxiety and Depression Scale. The quality of life was analyzed due to the score on the Ukrainian version of SF-36 survey. SIBO was diagnosed with the help of glucose hydrogen breath test. Statistical analysis was performed using IBM SPSS Statistics 17 software carried on Windows Vista (32-bit). Results. Patient group, which additionally used rifaximin for 14 days, demonstrated higher efficiency in abdominal pain relief (p = 0.037), decrease of anxiety (p = 0.01) and depression (p = 0.0007) level, and lower prevalence of SIBO (p ≤ 0.05) on the day 45 of the study. The hydrogen level in the exhaled air was significantly lower in this group. The quality-of-life domains “Bodily pain”, “Role emotional” and “Role physical” were significantly better in patients who received rifaximin (p ≤ 0.05). The significant difference was not observed in the intensiveness of bloating, heartburn, nausea, vomiting, and epigastric pain (p ≥ 0.05). Conclusions. The additional use of non-systemic antibiotic rifaximin demonstrated higher efficiency in decreasing abdominal pain intensiveness, improving anxiety and depression and quality of life levels in patients with IBS-C and AIT with hypothyroidism compared to the clinical guideline IBS-C management. SIBO prevalence and H2 levels were significantly lower on the day 45 of the study in patients who received rifaximin.