By a method quite simple in itself it is possible to measure the strength of acid and pepsin present in the gastric juice of the stomach. A test meal, spoken of as the Ewald test meal, is used. It consists of a small quantity of toast or crackers eaten with a cupful of tea or water. The contents of the stomach are aspirated in about half an hour after the meal is eaten. A small rubber tube (Rehfuss tube) is swallowed and the contents are drawn up through this with a syringe. Sometimes fractional test meals are used in which the aspirating tube is left in the stomach and samples of the contents or secretions are withdrawn at intervals of a few. minutes. A reading of 20° to 40° of free hydrochloric acid, and 40° to 60° total acid, which includes hydrochloric acid which has already become bound up with the food, are the average findings. The pepsin content of the gastric juice may be measured at the same time by testing its digestive power as shown by its dissolving effect on portions of coagulated egg white. On a chosen scale, pepsin should read between 200 and 300.
Attempts to study the digestive juices below the stomach have met with some degree of success. For a number of years several investigators have worked on this problem. It has been difficult to obtain the secretions as pure as they should be to give true information respecting their composition, strength, and volume.
Recently we have undertaken a study of the intestinal juices found in the duodenum. A similar tube is used as in aspirating the stomach. The peristaltic waves in the stomach carry the tip of the tube into the duodenum. The exact location of the metalic bulb can be seen with the fluoroscope, but for all practical purposes, marks on these tubes usually tell us when the bulb is in proper position for the collection of the duodenal juices. When the duodenal juices are draining properly they are colored with bile and contain no free hydrochloric acid.
The material obtained in this test is measured in amount to determine the rate of secretion. On a portion of it the icteric index is run routinely, so as to learn the relative amount of bile excreted. Other samples incubated for a proper length of time with prepared protein, starch, and fat enable us to estimate the amounts of these substances which can be digested by the particular sample obtained. These findings show the combined digestive ability of the pancreatic juice, and the intestinal juices mixed with it, so far as they exist in the resting duodenum. No method has yet been worked out by which the individual enzymes of the pancreas and small intestine can be estimated separately. Although this type of functional study has been done by various workers in recent years, still it is fairly new, and standards in interpreting the results are not as well established at present as we hope they will be later. In studying patients with functional intestinal digestive irregularities we have found that bile, and amylase (the starch-splitting enzyme) are frequently low. A deficiency in trypsin (the protein-‘ splitting enzyme) is occasionally encountered. A lack of lipase (the fat-splitting enzyme) is rarely found.
Stools may be examined for undigested food, but this gives rather slight satisfaction because after digestion in the small bowel, the food mass has been subject to the action of bacteria in the colon. Food which has escaped digestion by the digestive juices may have been changed materially by them.
Some workers in very recent months have suggested that the normal person not only makes enough digestive enzymes to combine with all his food in the intestines, but that he makes an excess which is absorbed into the blood stream. These enzymes in normal blood may digest there any incompletely digested food which has been absorbed. Incompletely digested proteins and other foods are often found in the blood following heavy meals. It is also known that the liver can complete the digestion of certain foods as the blood from the portal vein passes through it.
The Treatment of Indigestion Due to a Lack of Digestive Juices. Our food today is prepared in such a way that very little chewing is actually essential to the swallowing of it. The Indian who ground parched corn in his mouth necessarily chewed the corn well, and consequently secreted a large amount of saliva which was intimately mixed with his food. Now corn and wheat are ground far better than primitive man could grind them in his mouth. With. each meal we should have foods which necessitate some chewing. Dry toast and crackers are probably better digested than soft breads because they must be chewed before we can swallow them. There is some advantage in the starch granules being burst by the heat of baking. Soaking them avoids the need of chewing, and should not be done where one has a reasonable ability to chew.
Where there is an insufficiency of acid in the stomach, or where it is absent, we expect to find a disturbance of normal digestive processes. Some may even be born with an insufficient amount of acid in the stomach secretions or without the ability to make any. Approximately 50 per cent of cases studied by us at fifty years of age or above have shown a diminished amount of acid. As age advances the incidence of this condition continues to in-crease. To make up for the lack of acid, dilute hydrochloric acid has been prescribed by physicians for many years. Many patients do not tolerate this acid well when taken by mouth and its use involves a degree of annoyance in that a liquid medicine must be carried with one for use at each meal. When given in amounts up to about a teaspoonful of dilute acid with each meal, the digestion is usually improved to a degree. When more than this is used, patients at times complain of headaches or burning urine. Nature apparently uses a small amount of acid over and over again. It is mixed with the food, neutralized by food and other digestive juices, and the chloride thus formed is absorbed into the blood and ultimately reaches the glands of the stomach again where it contributes to the formation of more hydrochloric acid. There is never a large amount of acid present at one time.
For a number of years the authors have been using citric acid in place of hydrochloric acid. It may be used as it occurs naturally in citrus fruits or as the pure ,powdered acid dissolved in water at a concentration resembling lemon juice. Two ounces of lemon juice or six ounces of grapefruit juice should be taken with each meal. About a third of this is taken before beginning to eat, and the rest sipped while eating. If desired these acid juices may be combined with other fruit juices in drinks to be used as part of the meal. To many people the addition of sugar, which does not counteract the good effects of the acid, makes the juices more palatable. Incidentally, the sugar supplies additional calories often needed.
Or to arrive at the same results, we suggest a liberal portion of grapefruit for breakfast. Grapefruit is generally liked, and may be had anywhere. Custom teaches us to eat it first, and so place some acid in the stomach at the beginning of the meal. For each of the other two meals a large glass of lemonade made with two ounces of lemon juice serves the purpose well. Orange juice does not seem to contain enough acid to make up for the deficit clinically. However, lemon juice added to orange juice makes a very acceptable drink.
Lemon and catsup served commonly with shellfish, slices of lemon with other fish, and pickles served with a meat course undoubtedly aid in their digestion. Natural and cultured buttermilks are more easily digested than sweet milk, very probably because of their lactic acid content. In the days of our grandmothers, babies with digestive troubles were often given buttermilk with pleasing results. Today lactic acid milk is given success-fully by pediatricians to babies with certain types of in-digestion.
In a study of the peptic power of the gastric juice in several thousand test meals, we have found pepsin missing or low in about 30 per cent of all cases, and in 70 per cent of those having reduced acid. This deficiency may be remedied clinically by giving pepsin or pepsin mixtures after each meal. In treating pernicious anemia cases and others in whom pepsin is entirely lacking, we have been using experimentally, a crude pepsin. This form of pepsin, having a higher digestive power than the standard article, promises new help in compensation for this deficiency.
As we have suspected from the clinical symptoms, we frequently find variances in the duodenal enzymes. In our own series we have found bile missing or low in about 30 per cent of the cases studied. This is usually treated clinically by giving bile salts three times per day after meals. The fat-splitting enzyme, or lipase, has usually been present in supposedly normal amounts. In certain instances, the most marked deficiency is in the starch-splitting enzyme, or amylase. In other instances, the most marked deficiency is in the protein-splitting enzyme, or trypsin. We have found amylase more frequently missing than trypsin. Where amylase or trypsin is low we use enteric coated pancreatin tablets. Where bile and either amylase or trypsin or both are low or missing, we use an enteric coated combination of pancreatin mixed with bile salts.
In our search for normal controls we have found patients with a lack of sufficient digestive agents in the stomach, or patients with a lack of sufficient digestive agents in the small bowel, with no clinical symptoms of indigestion. In those with a lack in the stomach, we often find an increase in the digestive enzymes in the small bowel, and in other cases where the digestive enzymes in the bowel are low we have found an extra amount of digestive agents in the stomach. It would seem as if nature were trying to compensate in part for deficiencies. If there is this type of compensation and the patient is free from untoward symptoms, then additional digestive aids need not necessarily be given.
Vitamin B has an appetite stimulating power. It in-creases the flow of digestive juices and every diet should, of course, contain not a minimum amount of vitamin B, but according to those who have studied their effect most carefully, all vitamins should be used in several times the minimum amount required. Vitamin C is claimed to heighten the activity of the pancreatic juice.
Insulin, which isused chiefly in the treatment of diabetes mellitus, has been reported to increase the flow of digestive juice, and in many instances has been used with good results by those whose only symptoms pertain to irregular functioning of the digestive tract.
Where pain or griping is felt, or there is considerable gas, more attention should be given to the type of diet used,. These symptoms may be produced by colitis, but frequently they appear when food is of a type that will start up reflexes in the local nervous system. Coarse rough food will increase the distress. Soft and bland foods, or sometimes liquids only, do not produce physical irritation, but promote smooth easy internal activity. In addition to bland and non-residue foods, smooth alkaline mineral powders may be used effectively, when recommended by a physician. These act internally in a way resembling talcum powder externally.
Physiotherapy too in these instances is valuable. Fomentations or hot packs applied over the abdomen for twenty minutes to a half hour after meals often relieve pain and uncomfortableness. The hot water bottle or electric pad are good sources of heat. Their use intermittently for periods of a half hour probably gives better results than using them for hours at a time.
In the treatment of patients with indigestion in the presence of known digestive juice deficiency, we prefer to use the above mentioned simple, harmless digestive aids, rather than prescribing a too limited diet or severely limiting activities which will ultimately defeat the end desired.