en Gastroentrology Gastroentrology Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> Functional abdominal bloating is one of the functional gastrointestinal disorders (FGIDs). Here, we aimed to investigate and compare the effects of probiotics and colloidal bismuth subcitrate on abdominal bloating.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> This was a double-blinded randomized clinical trial performed on 125 patients with functional abdominal bloating in Isfahan in 2020-2021. At the beginning of the study, information on the frequency of abdominal bloating, its severity, the occurrence of early satiety, frequency of borborygmus, frequency of belching, and the frequency of defecation per week was collected. Patients were divided into 3 groups receiving familact probiotic pills that contained 7 bacterial strains, colloidal bismuth subcitrate tablets, and placebo pills for 4 weeks. Afterwards, the frequency and severity of abdominal bloating and other symptoms were compared.<span style="font-size:10.0pt"></span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b> After 2 weeks, patients in the probiotic group had a significantly lower frequency of abdominal bloating compared to other groups (P= 0.006). After 4 and 8 weeks, patients in the probiotic group and bismuth group had a lower frequency of bloating )3.18&plusmn;3.02, 4.11&plusmn;3.34) compared to placebo (5.10&plusmn;3.54) (P= 0.001 and P= 0.037, respectively). During the study, patients in the probiotic group had a significantly lower bloating severity (41.90% had no symptom) compared to bismuth and placebo groups (12.50 ,12.00% had no symptom) (p< 0.05). The frequency of borborygmus was significantly lower in the probiotic group after 2 and 4 weeks during the study compared to other groups (1.62&plusmn;0.2 Vs 2.69&plusmn;0.3, 2.45&plusmn;0.3 ) (P= 0.010 and P= 0.013, respectively).<span style="font-size:10.0pt"></span></span><br> <b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> According to our data, consumption of probiotics improves the frequency and severity of abdominal bloating and reduces borborygmus. Colloidal bismuth subcitrate also has significant effects.</span></span> Abdominal bloating, functional gastrointestinal disorder, Probiotic, Bismuth, clinical trial 518 525 http://caspjim.com/browse.php?a_code=A-10-2674-1&slc_lang=en&sid=1 Maryam Soheilipour maryamsoheilip@med.mui.ac.ir 100319475328460043051 100319475328460043051 No Isfahan Gastroenterology and Hepatology Research Center (IGHRC), Isfahan University of Medical Sciences, Isfahan, Iran Elham Tabesh tabesh.elham@gmail.com 100319475328460043052 100319475328460043052 No Isfahan Gastroenterology and Hepatology Research Center (IGHRC), Isfahan University of Medical Sciences, Isfahan, Iran Soheila Najmi so.najmi82@gmail.com 100319475328460043053 100319475328460043053 Yes Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mostafa Raisi mostafaraisi@yahoo.com 100319475328460043054 100319475328460043054 No Poursina Hakim Digestive Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Peyman Adibi adibi@med.mui.ac.ir 100319475328460043055 100319475328460043055 No Isfahan Gastroenterology and Hepatology Research Center (IGHRC), Isfahan University of Medical Sciences, Isfahan, Iran