Many people who eat beans will develop flatus as a result.


Beans contain oligosaccharides which the human body may not be able to split, such as:

(1) raffinose (trisaccharide composed of galactose, glucose and fructose residues)

(2) stachyose (tetrasaccharide composed of galactose, glucose, and fructose residues)


Clostridium species and other anaerobes in the colon digest these compounds with release of carbon dioxide and other gases. (Perchance beans will be banned to help control global warming.)


Factors affecting the amount of gas produced:

(1) amount of beans ingested

(2) concentration of undigestible oligosaccharides

(3) gastrointestinal transit time

(4) level of bacteria capable of digesting the oligosaccharides

(5) ingestion of enzymes capable of breaking down the oligosaccharides (Beano)


Differential diagnosis:

(1) gas from other poorly digested compounds, such as lactose in a patient with lactase deficiency


To read more or access our algorithms and calculators, please log in or register.