Flatulence, commonly known as passing gas or farting, is a normal biological process that everyone experiences.
In this article, we’ll talk about what causes excessive gas, how to manage it effectively, when to seek medical help, and more.
Table of Contents
What is Flatulence?
Flatulence occurs when intestinal gas exits through the rectum. Research shows most people pass gas 10-20 times daily, though this varies considerably based on diet, health, and other factors (1).
What Causes Flatulence
Let’s talk about the most common factors that can cause flatulence.
Swallowing Excess Air (Aerophagia)
Research shows that unintentionally swallowing excess air during eating and drinking can contribute to flatulence. This condition, medically termed aerophagia, may contribute to intestinal gas in people with digestive complaints (2).
Clinical research has identified several habits that significantly increase air intake:
- Rapid eating or gulping food
- Drinking carbonated beverages
- Frequent gum chewing
- Drinking through straws
- Smoking
- Poorly fitting dental appliances
Studies in pediatric populations have noted that children who eat quickly or consume many carbonated drinks often experience more flatulence due to increased air swallowing (3).
Gas-Producing Foods
Scientific research has identified specific food components that commonly increase gas production in the digestive system.
FODMAPs: These fermentable carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) significantly increase gas production when they reach the large intestine. Studies show that high-FODMAP diets produce substantially more hydrogen gas than low-FODMAP alternatives (4).
Fructans: These fermentable carbohydrates can significantly increase flatulence, particularly in people with irritable bowel syndrome, as shown in studies using low-FODMAP diets (5, 6).
Inulin and Fructo-oligosaccharides: These prebiotic fibers significantly increase flatulence in clinical studies. Research shows that chicory inulin and fructooligosaccharides increase gas production, even in healthy individuals (7, 8).
Beans and Legumes: Contrary to popular belief, research suggests that concerns about beans causing excessive gas may be exaggerated. Clinical feeding studies found that less than half of participants reported increased flatulence when eating pinto or baked beans daily, and only 19% of people experienced more gas with black-eyed peas (9).
Dairy Products: For people with lactose intolerance, limiting lactose intake to one cup of milk (240 ml) or less daily typically minimizes gas-related symptoms (10).
Sugar Alcohols: Clinical research demonstrates that sugar alcohols (like xylitol and isomalt) significantly increase flatulence compared to regular sugar. A randomized trial found that consuming 50g of xylitol substantially increased gas production, while erythritol at the same dose caused fewer symptoms (11, 12).
Medical Conditions Linked with Flatulence
Various health conditions can cause or contribute to excessive or smelly gas. Recognizing these associations may help identify underlying issues requiring treatment.
Irritable Bowel Syndrome (IBS): Flatulence is a prominent symptom in IBS patients. Clinical trials show that specific probiotics can reduce total IBS symptoms (including abdominal pain, distension, flatulence, and rumbling) by up to 42%, as compared to just 6% with placebo (12).
Small Intestinal Bacterial Overgrowth (SIBO): Research demonstrates a strong link between SIBO and excessive flatulence, particularly in patients with inflammatory bowel disease (IBD). Research shows that people with SIBO are nearly 5 times more likely to experience flatulence than those without this condition (13).
Lactose Intolerance: While flatulence is a common symptom of lactose intolerance, its diagnostic value varies widely. Systematic reviews show that flatulence alone is not a reliable indicator of lactose intolerance without other supporting symptoms (14).
Inflammatory Bowel Disease (IBD): Crohn’s disease and ulcerative colitis frequently present with flatulence as part of their symptom complex. Research indicates that digestive discomfort, which can include symptoms like excessive gas, is prevalent among adults living with IBD and can negatively impact quality of life (15).
Celiac Disease: Clinical research shows that many patients with celiac disease continue to experience digestive symptoms (including gas and bloating), even when following a strict gluten-free diet. A randomized controlled trial found that addressing additional dietary factors can significantly improve these persistent symptoms (16).
Gastroesophageal Reflux Disease (GERD): Flatulence remains a persistent symptom in GERD patients regardless of treatment approach. A 5-year randomized clinical trial found flatulence affected 40% of medically treated patients and 57% of surgically treated patients (17).
Treatment-Related Conditions: Certain medical treatments can induce or worsen flatulence. For example, chemotherapy for colorectal cancer frequently causes lactose intolerance, with 94% of patients with abnormal lactose absorption experiencing symptoms compatible with lactose intolerance, which typically include flatulence (18).
Medications That Increase Flatulence
Several medications have flatulence as a documented side effect.
Alpha-glucosidase Inhibitors: This class of diabetes medications (including acarbose) significantly increases flatulence compared to placebo (5% vs 0.5%), according to clinical trials (19).
Metformin: Standard metformin formulations cause flatulence in approximately 40% of patients, while extended-release formulations produce significantly fewer gas-related side effects (20).
Laxatives: Osmotic and stimulant laxatives commonly cause increased flatulence. Systematic reviews identify gas as one of the most frequent adverse effects in clinical trials of these medications (21).
Multiple Sclerosis Medications: Dimethyl fumarate therapy frequently causes gastrointestinal side effects, including flatulence. Research shows that bismuth subsalicylate (Pepto-Bismol) can help reduce the severity of this side effect (22).
Diagnosing Excessive Flatulence
When flatulence becomes problematic, healthcare providers use several approaches to identify underlying causes and develop targeted treatment plans. The diagnostic process typically involves multiple steps and may include specialized testing.
Medical History and Physical Examination
Diagnosis begins with a thorough review of your symptoms, medical history, and dietary patterns. Your doctor will typically ask about:
- When symptoms began and how they’ve changed over time
- Relationships between symptoms and specific foods or activities
- Eating habits, including the speed of eating and specific beverage choices
- Current medications and supplements
- Previous digestive conditions or treatments
The physical examination usually includes assessment of your abdomen for bloating, tenderness, and abnormal sounds (23).
Specialized Testing
Depending on your symptoms and initial assessment, your healthcare provider may recommend various diagnostic tests:
Hydrogen Breath Testing: This non-invasive test measures hydrogen levels in your breath after consuming specific sugars, like lactose or fructose. Elevated hydrogen indicates carbohydrate malabsorption or bacterial overgrowth, which are common causes of excessive gas (24).
Laboratory Studies: Blood and stool tests can help identify inflammatory conditions, infections, or specific digestive disorders that might contribute to increased gas production.
Imaging and Endoscopy: In certain cases, visualization of the digestive tract through X-rays, colonoscopy, or upper endoscopy may be necessary to rule out structural abnormalities or inflammatory conditions (25).
Food and Symptom Diary
Maintaining a detailed food and symptom journal is a valuable diagnostic tool that helps identify specific triggers. Research shows this approach effectively establishes connections between particular foods and increased gas production (26).
Treatment Options
Research supports several approaches to reduce excessive flatulence and related discomfort. These range from dietary changes to supplements, medications, and lifestyle modifications.
Dietary Approaches
Modifying your diet is often the first and most effective strategy for managing excessive gas. Several evidence-based approaches have shown positive results in clinical studies.
Low FODMAP Diet: This specialized diet limits fermentable carbohydrates that feed gas-producing gut bacteria. Studies show that following a low FODMAP diet significantly reduces flatulence and other gas-related symptoms, particularly in IBS patients (27).
Low-Flatulogenic Diet: Research demonstrates that diets specifically designed to limit gas-producing foods can reduce gas evacuations by up to 54% compared to baseline diets. These plans typically restrict fermentable fiber sources while maintaining nutritional adequacy (28).
Smaller, More Frequent Meals: Research suggests that eating patterns affect how gas moves through your digestive system. Studies have found that meal size, caloric content, and consistency can all influence gas dynamics (29).
Gradual Adaptation: Clinical research shows that the digestive system can adapt to foods that initially cause gas. Controlled studies found that regular consumption of gas-producing foods often results in fewer symptoms over time as gut bacteria adapt. In one study, participants who regularly consumed lactose experienced a 50% reduction in flatulence severity after an adaptation period, even if they were initially lactose intolerant (30).
Supplements and Medications
Scientific evidence supports several over-the-counter and prescription options for managing flatulence. These treatments work through different mechanisms to either reduce gas production or facilitate gas passage.
Targeted Probiotics: Specific probiotic strains have demonstrated effectiveness in reducing flatulence in clinical trials. Research reviews show that Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus casei, and Lactobacillus plantarum significantly improve gas-related symptoms, especially in IBS patients (31).
Alpha-galactosidase (Beano): This enzyme specifically targets complex sugars in beans and vegetables that humans cannot digest. Double-blind crossover studies show it significantly reduces flatulence events after high-fiber meals by breaking down oligosaccharides before they reach the colon (32).
Simethicone (Gas-X, Phazyme): While it doesn’t prevent gas formation, simethicone works by breaking up gas bubbles in the digestive tract, making them easier to pass. Clinical trials show the combination of simethicone with other digestive medications provides more effective relief than either treatment alone (33).
Bismuth Subsalicylate (Pepto-Bismol): This over-the-counter medication reduces digestive discomfort, including flatulence. Randomized controlled trials demonstrate that bismuth subsalicylate significantly reduces the severity of flatulence compared to placebo (22).
Activated Charcoal: Oral supplements and specialized undergarments containing activated charcoal can help reduce gas-related symptoms. Research shows that activated charcoal effectively absorbs intestinal gas and reduces the number of flatulence events after gas-producing meals (34). For smelly farts, specialized charcoal-containing devices can effectively neutralize gas odors, with research showing that some products can remove up to 77% of odorous sulfide gases (35).
Enteric-Coated Peppermint Oil: Clinical trials show peppermint oil capsules effectively reduce flatulence in IBS patients. In one controlled study, 79% of patients using peppermint oil reported reduced flatulence compared to just 22% in the placebo group (36).
Physical and Lifestyle Approaches
Several non-medical approaches have been shown to help manage flatulence with minimal risk of side effects.
Regular Physical Activity: Exercise significantly improves intestinal gas clearance, according to controlled clinical research. Studies show that even mild physical activity enhances gas transit and reduces bloating symptoms in patients with gas-related discomfort (37).
Optimal Body Position: Research demonstrates that being upright significantly improves gas transit compared to lying down. Experimental studies found that intestinal gas retention was much less, and gas clearance was expedited in the upright position (38).
Abdominal Heat Application: Clinical research shows that applying heat to the abdomen improves gastrointestinal motility and can reduce gas-related discomfort. In one randomized controlled trial, hot pack application significantly improved intestinal transit time and reduced the time to first gas passage (39).
Ginger Consumption: Ginger has traditionally been used to improve digestion and reduce gas. Modern research has found that ginger affects gastrointestinal function in ways that may assist with gas expulsion. One study found that ginger consumption increases lower esophageal sphincter relaxation during swallowing, which may facilitate the release of trapped gas (40).
Stress Management: Research indicates that stress and anxiety can worsen gas-related symptoms. Controlled studies show that targeted relaxation techniques, particularly relaxation response meditation, significantly improve flatulence in IBS patients (41).
When to Seek Medical Attention
While passing gas is normal, certain circumstances warrant professional evaluation. Contact a healthcare provider if your flatulence is accompanied by any of these concerns:
- Excessive gas that significantly impacts daily activities or quality of life
- Sudden, unexplained changes in your typical flatulence patterns
- Accompanying symptoms, like severe abdominal pain, persistent bloating, diarrhea, constipation, unexplained weight loss, or blood in stool
- Flatulence that remains problematic despite dietary modifications and over-the-counter treatments
- Symptoms that develop after starting new medications or treatments
Conclusion
Flatulence is a normal biological function influenced by numerous factors, including diet, health conditions, medications, and lifestyle habits. While occasional excess gas is common and typically harmless, chronic or severe symptoms may indicate underlying issues requiring attention.
Evidence-based management strategies include dietary modifications, targeted supplements, over-the-counter remedies, and lifestyle changes. These approaches can significantly reduce the frequency and impact of excessive flatulence for most people.
Remember that “normal” varies considerably between individuals. Finding your optimal approach to managing flatulence often requires some experimentation to identify what works best for your unique body and circumstances.