Bloating & Gas

Bloating describes the sensation of abdominal pressure; distension is the visible increase in girth. They often occur together but not always, and the distinction matters because their causes differ. Around one in five adults experiences bloating regularly, and it is among the most common reasons people reach for supplements. Three mechanisms account for most cases. First, gas production from bacterial fermentation of poorly absorbed carbohydrates — the FODMAP group of fermentable oligosaccharides, disaccharides, monosaccharides and polyols. Second, impaired handling of normal gas volumes: studies using gas infusion show people with bloating often have normal gas volumes but abnormal transit and distribution. Third, visceral hypersensitivity, where the same distension is perceived as far more uncomfortable, a hallmark of irritable bowel syndrome. Abdominophrenic dyssynergia adds a fourth mechanism, in which the diaphragm descends and the abdominal wall relaxes in response to modest gas, producing marked visible distension. Serious causes are a minority but must be excluded: coeliac disease, ovarian cancer in women over 50 with persistent new bloating, ascites, gastroparesis and pancreatic insufficiency. Persistent daily bloating that is new, progressive or accompanied by weight loss deserves investigation rather than dietary experimentation.

• •Abdominal fullness or pressure
• •Visible distension that often worsens through the day
• •Excessive belching or flatulence
• •Abdominal discomfort relieved by passing gas or stool
• •Clothing feeling tighter by evening
• •Nausea or early satiety

• •Fermentation of FODMAPs by gut bacteria
• •Irritable bowel syndrome with visceral hypersensitivity
• •Constipation and slow colonic transit
• •Small intestinal bacterial overgrowth
• •Lactose or fructose malabsorption
• •Coeliac disease
• •Abdominophrenic dyssynergia
• •Aerophagia from rapid eating, gum or carbonated drinks

{"Excess fermentable carbohydrate reaching colonic bacteria","Abnormal gas transit and distribution rather than excess gas volume","Heightened visceral sensitivity amplifying normal distension","Uncoordinated diaphragm and abdominal wall responses to gas"}