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I am sorry I am posting all this info. Hope people are interested. However just the mind numbing act of typing helps me get my mind off other things. So I do it. I do hope somebody reads it and finds it interesting or useful or something.Here is some more info about gas - gas from scratch as it wereNormal Intestinal Gas DynamicsIntestinal gas is a simple balance of four dynamic processes 1) swallowing and eructation(burping) 2)production and consumption of gases by luminal bacteria 3)absorption through gut mucosa and elimination through the lungs and 4) expulsion from the rectum (flatulence). A….Oxygen and nitrogen are the predominant gases in swallowed air, and these gases diffuse freely across the gastric mucosa. The gas that leaves through the pylorus is the gas that is swallowed but not eructated and not absorbed. Bicarbonate is then secreted by the pancreas and reacts with protons from gastric acid, forming carbon dioxide, which is absorbed and ultimately released through the lungs. Thereafter, there is no other gas production until a non absorbable but fermentable substrate, such as lactulose, sorbitol, or in some people malabsorbed lactose or fructose reaches a bacterial colony. The required concentration of this bacteria, under normal circumstances, is only found in the colon. The bacteria then break down the substrate to hydrogen, carbon dioxide, and trace gases. The hydrogen is then either absorbed by diffusion or consumed by other bacteria to reduce carbon dioxide to methane or acetate and reduce sulphates to sulfides. The trace gases are primarily responsible for the odor of rectal gas, whereas nearly all gases expelled are odorless….Approximately 15% of [patients are methane producers rather than hydrogen producers; the predominant; the predominant methanogen in humans is Methanobrevibacter smithii….An acidic milieu(in the colon) inhibits bacterial activity…..Bacteria represent the sole source of gut hydrogen, making this particular gas attractive for the identification of bacterial overgrowth states…Gnotobiotic (germ free) mice and young infants whose colons have not yet been colonized have no significant breath hydrogen. Adults all have hydrogen found in the breath from bacterial fermentation of undigestible carbohydrates.Hydrogen gas is produced at a rate of 4l for every 12.5 g of undigested carbohydrate, yet only a much smaller volume is excreted by the various routes. The reason for this inconsistency is that, as described above, hydrogen is also consumed by bacteria, especially methanogens. Approximately 20% of all hydrogen is eliminated via the lungs; the rest is either consumed or expelled by via the rectumFrom- Using Breath tests wisely.... by Joseph Romagnuolo et al. AJAG may 2002

 

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It is a paper called Using Breath test wisely in a Gastroenterology Practice. American Journal of Gastroenterology, May 2002