The term peritonitis has been made to cover so many conditions, of widely differing pathological character, that it is intended here to consider only those which have a practical interest for the surgeon. It is unfair both to terminology and pathology to include under the same name conditions that may be brought about slowly, or without any participation of bacteria, with those which are due solely to bacterial invasion. No attempt will be made here to go into a minute or complete classification of the various conditions included by different writers under this name. For instance, they have spoken of an idiopathic form of peritonitis, thus confessing by use of this adjective ignorance of the etiology of the condition. The surgeon has neither use for such an expression nor belief in such a possibility. The thickening of the peritoneum which may result from the proximity of an old hemorrhage, or the irritation produced by the circulating fluids in cases of Bright’s disease, is for him an entirely different entity, and is neither an idiopathic form nor peritonitis itself.

For surgical purposes we mention especially the following forms:

Forms A, B, and C may merge into one another or be confused from the beginning, or they may themselves be consecutive to D, while E, the malignant form, is hardly a distinct type, but rather a peritoneal expression of a more widespread general condition.

Again writers have endeavored to make distinctions by the use of such terms as “virulent,” “septic,” “putrid,” between which, however, no lines can be clearly drawn nor sharp distinctions made. They depend to some extent on the nature of the bacterial invasion, and again upon the actual virulence of the bacteria involved. The most distinctive type of surgical peritonitis is the tuberculous, which is usually relatively slow and recognizable as such, but as between the cases produced by spreading erysipelas, gonorrhea, intestinal perforation or postoperative infection one can make few, if any, distinctions which are serviceable or useful.

Anatomically considered there are two types of great importance—the circumscribed or local and the general or diffuse—prognosis depending in no small degree upon the extent of limitation of the active process, while at any time the former may merge into the latter. Consecutive peritonitis may include that which is the result of direct extension, as from erysipelas, appendicitis, acute cholecystitis, pyosalpinx, or other acute infections which have spread to and involve this membrane. Under this head also may be included those cases due to thrombosis or embolism, of mesenteric or other vessels, which lead to speedy gangrene of a part or all of the intestine.

Traumatic peritonitis refers rather to those cases where infection has been carried directly inward from the exterior. Traumatic peritonitis may be the result of extension of the same conditions which produce the first, the consecutive form, or only occur more directly, as, for instance, those cases produced by rupture of the stomach or duodenum after ulcerations of the same, or perforation of typhoidal ulcers, actual rupture and escape of the contents of a suppurating gall-bladder, appendix, tube, or any other collection of pus, or perforation due to the gradual extension of tuberculous, syphilitic, or malignant disease, with final rupture of a viscus.

The nature of the bacterial invasion is of more interest to the pathologist than to the surgeon as such. In general, however, it may be said that, in addition to the ordinary pyogenic organisms, the colon bacilli are perhaps the most frequently to blame, while the more putrid types are the result of actual escape of bacteria from the intestine, as through a perforated appendix, and the addition of a mixed type to one which began perhaps as a simple one. Thus in the so-called putrid forms multiple bacterial contamination is usually discovered upon making cultures. The pneumococcus, the capsule bacillus, and the gonococcus are also not infrequently found, in cases of peritonitis whose nature and origin will be suggested by the discovery of the particular germ involved in each case.

Symptoms.

—While varying much in time and intensity, and even completely changing their type during the successive stages of the disease, there are, nevertheless, certain cardinal symptoms which are universally recognized in cases of surgical peritonitis. These include vomiting, pain, tenderness, with more or less shock, followed sooner or later by abdominal spasm and distention, while to these symptoms there is sure to be added bowel obstruction of some type which becomes, toward the end, perhaps the most profound feature, and which may even mask the significance of other symptoms. According as the lesion is localized or generalized pain may be referred to a particular area or may be general and intense. Local pain, with tenderness, usually implies, at least at first, a localized lesion, and is not so likely to be accompanied by vomiting as the more diffuse form. Depression is found to correspond largely to the type and degree of sepsis, while collapse is a prominent feature in the more severe cases. The pain, which is sometimes intense, subsides, and it should be emphasized that a speedy subsidence is not necessarily a favorable symptom. It too often marks the transition of an ordinarily acute case into one of intensely septic or even putrid type. Tenderness may be acute and localized, or diffuse and only evoked on deep pressure. One of the most significant symptoms is abdominal rigidity, which persists throughout the active state of the disease, and which, when followed or accompanied by meteorism, may to some extent mask and obscure all conditions within. If the patient be not seen until this stage is reached diagnosis can be made only by history and conjecture, for it is almost impossible to determine anything by palpation.