As the frequency and amount of the intestinal evacuations may thus vary according to the nature of the diet, without necessarily involving any disturbance of health, so may they also vary according to the state of the other excretions; and hence, again, is evident the absurdity of considering the same standard as applicable alike to all persons, times, and circumstances. If, from continued exertion, perspiration is kept unusually active, the excretion from the bowels may be proportionally diminished, not only without injury, but even with advantage to the health; because, if the same waste were to go on by the bowels as before, and the increased exhalation from the skin also to continue, the system would speedily become reduced. In consumption, for example, exhausting bowel-complaint and profuse perspiration are frequently observed to alternate, and whatever remedy is given to check the one generally aggravates the other. But if _both_ were to run their course together, instead of singly, how much more rapidly would the system be undermined! From this relation between the different excretory functions, it follows, that when sluggishness of the bowels is induced by excess in another excretion, the first step ought to be to remove or diminish the unnatural stimulus which has occasioned that excess, before attempting, by means of purgatives, to _force_ the bowels to act. If the cause which has produced the deviation from the due proportion of the excretion be left unabated, the only effect of strong laxatives will be, not to relieve, but to irritate and weaken. The mere fact of the bowels not being emptied so frequently as usual, is therefore, when taken by itself, no evidence that they ought to be stimulated by medicine. Before coming to this conclusion, we ought to determine clearly whether the diminished action results from morbid sluggishness of the intestinal canal, or is the natural result of an accidental change of diet, or temporary excess in the other excretions; because the remedy which is appropriate and efficacious in the one case, may be altogether inapplicable to the other. Where it arises entirely from the aliment leaving little residual matter to be thrown out, the health may suffer _from the diet being inappropriate_, but it will not suffer merely from the diminished action of the bowels. Whereas, when the diet is of the ordinary mixed kind, and the costiveness proceeds from morbid inaction, then general derangement of the system will be induced, unless the bowels be attended to, and their natural action restored. This distinction ought never to be lost sight of.