By flatulence we mean the formation of gases in the intestine. They are formed by the action of bacteria upon the residue of the food which has been absorbed, and particularly upon the cellulose contained therein; the latter is then split up into volatile fatty acids (butyric acid, acetic acid) and into gases (carbon dioxide, hydrogen, and methane). The more cellulose there is contained in the food, the more there is usually eliminated as residue, thus facilitating the production of such cleavage products. Consequently, a diet rich in cellulose will form much gas. This may be noticed when leguminous vegetables, especially beans, have been eaten ; cabbages also pro-duce the same effect, on account of the cellulose and sulphur contained in them. Black bread, e.g., rye bread, also causes considerable flatulence.
On the other hand, a diet which forms but little residue may also produce gases when certain bacteria have been introduced with it. Unclean water, previously in contact with a slimy river-bottom, will often cause discomfort by colic and the formation of gas. I myself noticed this during my stay in Toronto, in Canada ; on drinking the water of the large lake, I was constantly troubled with gases and colic. The same was the case soon after, when I was in Detroit and drank the water from Lake Michigan. In both these places I experienced no such trouble when drinking pure mineral water.
Mineral waters which are badly bottled, so that unclean substances are mixed with them, may give rise to the same symptoms. It is necessary, for this reason, to make a careful selection from among such waters. Above all, it is necessary that the authorities should make a thorough investigation of every mineral spring of which the water is universally used, as well as of the bottling plants. Impure milk, made so by secret dilution or the inadvertent admixture of any unclean substance, will very frequently cause the development of gases. Flatulence may also be noticed when large quantities o,f good milk are taken.
Flatulence very readily occurs when the residue of the food remains too long in the intestine. The longer the feces are retained in the intestine, the longer the bacteria act upon them, thus causing fermentation and decomposition. The greatest number of bacteria is found in the colon, and the feces contained therein form the most favorable nidus for them.
A plentiful meat diet also favors the formation of gases when the former contains much connective tissue, since, owing to the large quantity of meat and the resistance offered by the connective tissue, the digestive fluids are not able to fully digest it, and a considerable portion remains to be subjected to the action of the bacteria in the colon. The longer it remains there, the more gases may be formed. In order to prevent the formation of gases it is important that the feces be expelled from the intestine as soon as possible. Constipation must therefore be avoided. The means for its avoidance will be considered elsewhere.
Persons having a tendency to flatulence should avoid foods which contain much residual matter, such as beans, lentils, and the cabbage varieties, in which not only the cellulose, but also certain other components, viz., sulphur compounds, cause the formation of gases. In the diet of such persons all indigestible foods should be avoided and care be taken that the diet be so composed that its greater portion be absorbed in the upper intestine, so that a very small quantity will be subjected to the action of the bacteria. Especially in the case of aged persons should a careful choice of foods be made, as in them the intestines are relaxed and dilated, and the residue is apt to be retained in the bowel for a longer time. We are thus, to be sure, placed in a dilemma, as when the food contains too little refuse matter the residue will for this reason remain too long in the intestine. Such feces, however, are not apt to cause flatulence. We must consequently endeavor to steer between two cliffs.
The foods causing the most flatulence, such as leguminous vegetables, cabbage, black bread, etc., must o,f course be eliminated from the diet, and when necessary milk must also be forbidden or only allowed in small quantities, Care must also be taken that its origin be irreproachable. A diet easily digested must be adhered to; it may be composed of tender meat, ham, eggs, rice, tapioca, sago, fine white bread, zwieback, etc. Potatoes are only allowed when mashed, as fried or roasted potatoes give rise to flatulency. Bread made with a sour dough should be avoided, as in this way large quantities of bacteria are introduced. Whatever might cause fermentative processes must be usually avoided. Beer especially is forbidden. Tea or even a little red wine might be used to advantage.
In the dietetic treatment of flatulence a principal factor is the avoidance of foods containing much residue. Although such a diet is useful in persons subject to this disturbance, it is not indicated for those in good health, as it may give rise to constipation. The formation of a small amount of gas is not to be regarded as an evil, since it materially aids the movement of the bowels and the ejection of their contents. It is only the presence of excessive flatulence which should be combated, especially when diseases exist in which the raising of the diaphragm must be prevented, as in heart affections. In many cases of arteriosclerosis flatulence, which is frequently present, gives rise to troublesome effects. The best treatment for flatulence consists in the. rational diet above described. The best preventive measure in conjunction with the same would be that all o,f the food, and especially the vegetables and other cellulose-containing substances, be most thoroughly masticated, in order that no undigested portions reach the intestine, and there form a nidus for the development of some of the countless bacilli which are ingested from the air or with the saliva or in the foods themselves.