Indigestion and constipation are observed by asthmatics to be predisposing causes of many attacks. They provoke attacks of asthma as the same conditions aggravate capillary bronchitis. There is no doubt that in some cases the toxins absorbed from the intestinal tract play a part in producing the disease.

Asthmatics very frequently exhibit idiosyncrasies. As certain perfumes cause attacks in some persons, so will certain foods in others. When diet plays any part in bringing on disease, the case must be studied with care as to the influence of each article of food; for instance, pork may provoke attacks in one person and lobsters or other sea-food in another. Strong coffee, on the other hand, will sometimes shorten attacks. Many patients must avoid starches and sugars, or use them with great moderation. In many cases peculiarities of diet play no part in the causation of asthma, and for such, a dietetic prescription is unnecessary. It is alway well, however, when attacks occur during the night or early morning, to forbid a heavy evening meal, and especially to warn the patient against taking any food whatever late at night.