Just as everyone goes to the bathroom, everyone also passes gas; it's simply a biological reality. Your body is able to absorb a limited amount of the gas it ingests or produces. The rest has to come out somewhere. Even though flatulence is normal, its presence can cause anxiety and panic- both for the person releasing the gas, and those who may be in the vicinity. For this reason, reducing flatulence is of interest to many people, especially if they feel like their body is producing an excessive amount. However, it's difficult to remedy a situation without understanding what's causing it, so let's take a look at six common causes of flatulence.
What Causes Flatulence?
1. Intestinal Bacteria
Most of the flatulence your body produces is due to intestinal bacteria, which create methane, and other gases, as a byproduct of digestion. Imbalances between unhealthy bacteria and healthy probiotic colonies can influence how much intestinal gas a person may produce. Persons with healthier intestinal colonies typically experience less flatulence; persons with unhealthy imbalances experience more. This is one reason why experts encourage the maintenance of healthy intestinal flora by taking a probiotic supplement. According to the Department of Medicine at UMDNJ-Robert Wood Johnson Medical School in New Brunswick, flatulence and bloating tend to improve when intestinal flora is balanced. 
2. Low-Digestible Carbohydrates
You may have seen candy or snacks that is advertised as "having a low impact on blood sugar" but contains 15 grams of "sugar alcohols" on the nutritional label. Sugar alcohols are an example of low-digestible carbohydrates (LDCs). LDCs are carbohydrates that may be added for flavoring purposes but are not absorbed by the small intestine and don't provide that much nutritional effect. This may be desirable for persons hoping to manage their blood sugar or caloric intake. However, even though digestive enzymes do not break down these carbohydrates, they're not exactly a freebie. The University of Minnesota Department of Food Science and Nutrition warns that LDCs may produce diarrhea and flatulence.  One sugar alcohol specifically, Sorbitol, has even been implicated as the source of a phenomenon dubbed, "Halloween Diarrhea." 
There have been a lot of surgical advances made over the years and some procedures can be performed in very minimally invasive ways. Some cannot, and even routine surgery can result in anatomical reconstruction. Some patients who have had surgery for gastroesophageal reflux have reported experiencing increased bloating and flatulence afterward. 
Also known as the musical fruit, many people believe eating legumes will cause intestinal gas or flatulence due to high fiber content. Researchers at the School of Nutrition and Health Promotion at Arizona State University evaluated the outcomes of several studies that examined the link between beans and flatulence. Although it was deduced that increased fiber intake can produce intestinal gas, they were also quick to mention that concerns about excessive flatulence from eating beans have been slightly exaggerated. 
5. Intestinal Disorders
Intestinal disorders are common and produce a range of concerns. IBD is a source of constant discomfort for many people. Some estimate that up to 85% of persons with Crohn's disease suffer from malnutrition. Lactose intolerance, which is widespread among otherwise healthy persons, can also cause diarrhea and bloating. According to the Department of Gastroenterology at Guy's and St Thomas' NHS Foundation Trust in London, flatulence is a symptom shared by many intestinal disorders.  
6. Harmful Organisms
Like intestinal disorders, harmful organisms disrupt the body and disturb the digestive system. Researchers at the Department of Tropical Medicine at Egypt's Ahmed Maher Teaching Hospital evaluated stool samples from patients suffering from diarrhea and flatulence and found that harmful organisms infected over 60% of those evaluated.  
- Ebert EC. The thyroid and the gut. J Clin Gastroenterol. 2010 Jul;44(6):402-6. doi: 10.1097/MCG.0b013e3181d6bc3e. Review.
- Grabitske HA, Slavin JL. Gastrointestinal effects of low-digestible carbohydrates. Crit Rev Food Sci Nutr. 2009 Apr;49(4):327-60. doi: 10.1080/10408390802067126. Review.
- Breitenbach RA. 'Halloween diarrhea'. An unexpected trick of sorbitol-containing candy. Postgrad Med. 1992 Oct;92(5):63-6.
- Zingg U, Oertli D. [Functional syndromes after surgery of the upper gastrointestinal tract]. Ther Umsch. 2012 Jan;69(1):39-47. doi: 10.1024/0040-5930/a000249. Review. German.
- Winham DM, Hutchins AM. Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutr J. 2011 Nov 21;10:128. doi: 10.1186/1475-2891-10-128.
- Lomer MC. Dietary and nutritional considerations for inflammatory bowel disease. Proc Nutr Soc. 2011 Aug;70(3):329-35. doi: 10.1017/S0029665111000097. Epub 2011 Mar 30. Review.
- Lomer MC, Parkes GC, Sanderson JD. Review article: lactose intolerance in clinical practice--myths and realities. Aliment Pharmacol Ther. 2008 Jan 15;27(2):93-103. Epub 2007 Oct 23. Review.
- Mousa KM, Abdel-Tawab AH, Khalil HH, El-Hussieny NA. Diarrhea due to parasites particularly Cryptosporidium parvum in great Cairo, Egypt. J Egypt Soc Parasitol. 2010 Aug;40(2):439-50.
- Amin N. Giardiasis: a common cause of diarrheal disease. Postgrad Med. 1979 Nov;66(5):151-6, 158.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.