Tuberculosis is an infectious disease, due to the presence in some part of the body of the Bacillus tuberculosis. The disease may be either acute or chronic, but fever is present whenever there is an exacerbation of the symptoms. The latter are both local and general, and vary with the particular organ or organs affected, but the lungs constitute by far the most frequent site for the development of the germs. The bacillus produces from the tissue or "soil" in which it grows a toxin or poisonous substance which enters the circulation by absorption and which modifies nutrition, causing pyrexia and an increased production of tissue waste, with more or less rapid emaciation.

Several factors combine to disturb the digestive system. These are:

1. The fever itself.

2. The impoverished condition of the blood, which affects the quality and quantity of the digestive juices.

3. In pulmonary tuberculosis, after the expectoration becomes considerable it is often ropy and tenacious, and some of it is liable to adhere to the surface of the mouth or pharynx, and be swallowed with the food or saliva, with the result of exciting gastric and intestinal catarrhs, or possibly of locally infecting* the mucous membrane of the intestine with the bacilli, which produce ulceration with further impairment of digestive functions and absorption.

The prognosis of a given case depends very largely upon the digestion.

General Consideration Of Dietetic Treatment

Proper dieting is unquestionably one of the most important factors in the prophylactic as well as the active treatment of pulmonary tuberculosis, and in prescribing a regimen many things must be taken into consideration besides the mere classification and selection of food. The disease may be exceedingly protracted, lasting for years, with intervals in which the patient enjoys a comparative degree of health and comfort, which temporarily emancipate him from dietetic restrictions. But even then he should see to it that his food is ample for his bodily needs. Malnutrition at any time may permit the renewed activity of a latent tubercular process, and, on the other hand, an increase in body weight is accompanied by marked improvement in the symptoms of the disease.

The disease being very chronic the pecuniary circumstances of the patient must be considered. By ordering him to abandon his only means of livelihood or to undertake a long and expensive journey he may be so impoverished that he cannot afford to procure the best food, which is so essential both to repair the tissue waste, which sooner or later is a prominent feature of the disease, and to supply energy; and good climate is of little use unless it helps him to acquire a better appetite and easier digestion.

The appetite, too, must be consulted. It is sometimes better to humour whims than to seek to combat them, and inflexible rules can no more be enforced for dieting than for medication. The appetite is often very poor or capricious, and the physician's dietetic expedients will be severely taxed to devise suitable foods which meet all requirements. The patient should be given a list of foods which he can regularly eat, foods to be avoided, and foods which he may have as an occasional indulgence.

Young phthisical girls especially may long for sweets and confectionery, and despise the more wholesome animal food; in fact, some writers regard this as a symptom of the disease in such cases. If they cannot have what they crave they will refuse what they are allowed, and much tact and persuasion is required to induce them to eat rationally.

Since so much depends upon sustaining the nutrition and strength of tuberculous patients, it is of the utmost importance to keep the stomach and bowels in the best possible condition.

Patients should be warned never to swallow the sputum, for this always excites dyspepsia, and sooner or later gastric catarrh. The occurrence of the latter is also favoured by the habit, which many patients acquire, of perpetually taking cough medicines and patent "sure cures," many of which contain potassium iodide and other gastric irritants. In advanced cases the catarrh may be a sequel to enfeebled circulation.

All food should be fresh and carefully selected, and the cooking should be as simple as possible without monotony. Viands should be savoury, and served in a manner to tempt the palate.

The most important articles of diet for the consumptive are the animal foods, and milk, beef, and fats and oils should form the essentials, rather than too much meat; but in ordinary cases any variety of properly cooked animal food may be eaten. Starches and sugars are allowable in milder cases, but never to the exclusion of nitrogenous aliments, and not at all if gastric catarrh exists.

In phthisis there often seems to be a failure to assimilate amylaceous and saccharine food, which is beyond that which is explainable by the presence of catarrhal conditions. These substances, which ordinarily furnish a large proportion of the energy of the body, in tuberculosis appear to do so less readily than the fats and proteids. Growing children, however, require more carbohydrates than do adults. Malt is especially valuable as a tonic in tuberculosis, and the diastase aids assimilation of farinaceous foods.

Great diversity exists among different phthisical patients in the power of assimilation of food, and even in individual cases during the progress of the disease.

Bauer says: "One not infrequently sees phthisical patients who consume the full hospital diet without any visible ill effects, although their evening temperature oscillates between 1020 and 1040 F. With such patients one need feel no anxiety as to the choice of foods, provided their nutritive value be the same".

Rest is important in its relations to digestion, and patients should not eat when fatigued. Great benefit is often derived by lying down and quietly resting, even without sleeping, for half or three quarters of an hour before dinner and supper. It is best to take the principal meal in the middle of the day unless there is fever at that time or soon after it, in which case a hearty breakfast and a light lunch will be better borne.