Spotlight on abdominal bloating
Bloating is common throughout the world, is strongly associated with abdominal pain, and may improve with adequate doses of rifaximin, recent studies found.
Two recent studies focused on the prevalence of abdominal bloating, associated factors, and rifaximin as a potential treatment.
The first study found that nearly one in five people worldwide experience bloating as a symptom and that bloating is strongly associated with abdominal pain. Researchers analyzed Rome Foundation Global Epidemiology Study internet survey data on diet, medical history, quality of life, and Rome IV diagnostic questions among 51,425 individuals in 26 countries, including the U.S. They defined presence of bloating as experiencing bloating at least once per week for the past three months and excluded respondents with potential organic causes of bowel symptoms. Results were published June 12 by Gastroenterology.
Nearly 18% of the global study population reported bloating, ranging from 11% in East Asia to 20% in Latin America. Prevalence decreased with age, and women were about twice as likely as men to report bloating. More than half of those who reported weekly epigastric pain (71%), nausea (60%), or abdominal pain (62%) also reported bloating at least once per week. After the researchers controlled for demographics, diet, and psychological burden, respondents who reported abdominal pain at least once a week had increased odds of bloating (odds ratio, 2.90), as did those who reported epigastric pain (odds ratio, 2.07), whereas those who reported constipation alone had a significant but weaker predictive association (odds ratio, 1.75). Bloating was also more common among those meeting Rome IV criteria for one or more of 22 disorders of gut-brain interaction, with the prevalence ranging from 21% (functional diarrhea) to 74% (epigastric pain syndrome). The survey relied entirely on patient-reported data and did not differentiate bloating from abdominal distention, among other limitations, the study authors noted.
The second study, a systematic review and meta-analysis, found that rifaximin therapy is associated with an increased likelihood of improvement in bloating and distention. Researchers identified 10 randomized, placebo-controlled trials that utilized the nonabsorbable antibiotic in 3,326 patients with functional GI disorders (FGID). Rifaximin was administered in doses ranging from 400 to 1,650 mg per day for one to two weeks. The researchers excluded observational studies, those including patients with organic bowel disorders (e.g., inflammatory bowel disease), and those in which rifaximin was given for other indications, such as hepatic encephalopathy. Results were published June 14 by the Journal of Clinical Gastroenterology.
Rifaximin therapy led to a higher likelihood of improvement in symptoms of bloating (44.6% vs. 34.6%; risk ratio, 1.22 [95% CI, 1.11 to 1.35]; n=2,401), without significant heterogeneity; however, daily doses of less than 1,200 mg/d were similar to placebo (P=0.09). In seven studies that subjectively quantified bloating, rifaximin led to a greater reduction in bloating scores compared with placebo (standardized mean difference, −0.3 [95% CI, −0.51 to −0.1]; P=0.04), albeit with significant heterogeneity. The study included patients with FGIDs regardless of their classification and the presence or absence of small intestinal bacterial overgrowth, among other limitations, the authors noted. “[Rifaximin] therapy utilizing a dose of 1650 mg/day (as 550 mg thrice daily) and a duration of 2 weeks was consistently associated with improvement compared to placebo, lower doses, and a shorter duration of therapy,” they wrote. “In light of established safety, it may be offered to patients with FGIDs symptomatic with bloating or distension who fail to improve on diet modification alone.”