Again, first class of causes of indigestion includes such errors as that of eating too hastily, taking food immediately after great exertion, or performing hard work, engaging in mental toil, or taking vigorous exercise, immediately after meals. As a cause of indigestion, also belonging to this class, must be included mental emotion, such as anxiety, alarm, or the emotions roused by the receipt of bad news, &c. In most cases, perhaps, the latter cannot be reme died ; but, as regards the former, it should be a rule to rest a short time after bard work before partaking of food, and to occupy one's self with light employment for a short time, half an hour or an hour, after a full meal.
II. Causes of Indigestion connected with the Process and Organs of Digestion.—The second class of causes includes circumstances many of which have been already noticed. Imperfect chewing, either because the food is bolted, or because the teeth are bad or want ing, is one rather common cause of this class. Others are connected with the state of the stomach and the character of its digestive fluid. Thus, catarrh of the stomach, the result of a common cold, causes loss of appetite, &c., and most of the other diseases of the stomach act similarly. Acidity and heartburn, common symptoms of dyspepsia, arise from excess of acid, and are due to organic changes in the glands of the stomach ; and so on. Similarly, conditions of the bowel, of the liver, and of the pancreas, all parts of the digestive apparatus, will act as causes of indigestion.
There is one circumstance which must not be overlooked. Undigestible material taken in with the food should pass through the bowel and be duly expelled. It has been explained also that certain waste substances, excreted by the liver, are passed into the bowel for expul sion. Now if for any reason these two kinds of waste substances, mixed together in the bowel, are not expelled so speedily as they ought to be, they are all the time undergoing putrefactive changes, and chemical changes of various kinds, by which in the fermenting mass there are produced foul gases and new sub stances poisonous to the body. If the material is not voided in proper time, the gas is liberated in the bowel, distending it and producing some of the more troublesome symptoms of indi gestion.
But the chemical poisons (toxins they are called) are absorbed, and they act chiefly on the nervous system. Thus there are numerous disorders of the general system undoubtedly due to poisons manufactured in the body itself in this way, of which no symptom draws the slightest attention to stomach or bowels or sug gests that the real source of the mischief is a fault in any of the processes associated with digestion. There is no longer ally doubt, for
instance, that some of the worst and most per sistent forms of anaemia are due to intestinal toxins, to poisons, that is, produced in stomach or bowels by some flaw in the chemical part of the digestive process, or by delay in the evacua tion of the waste from the bowel. The latter cause may exist, it should be observed, even when the bowels are moved daily, for it is clear that though the bowels may move every day, the whole of the material that should be ex pelled may not be so. Perhaps what is being daily expelled is only the excess, the overflow so to speak, what the bowel cannot hold. So that, while a person imagines, because he has a daily movement, that his bowels, at any rate, are all right, it may be that all the time the lower bowel is full, ejecting only what, with the constant additions it is receiving from above, it can no longer hold.
III. Causes of Indigestion connected with other Organs or General Conditions of Body.—The third class includes a great variety of conditions which affect the process of digestion directly or indirectly. Thus an tends (bloodlessness) is in women a very common cause of dyspepsia, because the blood is not in proper condition to afford to the stomach the material for the formation of gastric juice in proper quantity and of proper quality, and be cause other parts of the digestive process are similarly affected. Diseases of the heart and lungs, by hindering the proper circulation of the blood, speedily affect the functions of the stomach and bowels. The nervous system regu lates every function of the body, and conse quently nervous diseases have some kind of dyspepsia as one of their symptoms. Properly speaking, in such cases the indigestion is not a disease in itself ; it is only a symptom of a dis ease. In many, however, it may be so promi nent a symptom as to blind to the fact that it is really only a sign of some other derangement which Must be discovered.
It is worthy of special notice that in women dyspepsia is a very common result of tight lacing, because the pressure does not permit the healthy action of the liver, and induces other changes in the abdominal organs, of which the indigestion is one of the early ex pressions,