Acute inflammations may be produced by the action of irritant poisons which have been swallowed, the inflammation here being accompanied by sloughing. Phlegmonous inflammation is rare in the stomach as compared with the frequency of phlegmonous angina of the fauces, or dysenteric inflammation of the intestine. A localized and a diffuse form have been described, the latter occupying the stomach wall extensively, and causing great thickening. There is great swelling and redness of the mucous membrane, terminating in purulent infiltration of the wall of the stomach, chiefly in the submucous tissue. Sometimes multiple abscesses form in the wall of the stomach and burst into its cavity. It has been found in some cases to be related to an invasion of streptococci, in this and other respects resembling erysipelas. It may take origin in an ulcer or ulcerating cancer, but frequently the origin of the infection is obscure.

Fig. 3S9. - Gastric diverticulum near greater curvature.

Catarrh of the stomach, on the other hand, is a condition of very frequent occurrence and is met with in the acute and chronic forms.

Acute Catarrh

This is induced for the most part by the direct action of irritants on the mucous membrane, mainly by the use of irritating foods or drinks. When food remains in the stomach undigested it undergoes decomposition, and the irritating products may induce an acute catarrh. The mere prolonged stay of food in the stomach probably induces it, as when by exposure to cold the secretion of the gastric juice and the peristaltic action necessary to the process of digestion are interfered with.

It is seldom that the stomach can be examined after death in this condition, but from the observations of Beaumont on his patient with a gastric fistula, as well as from experiments on animals, the appearances of the mucous membrane have been tolerably well made out. There is intense redness with swelling of the mucous membrane, which is covered by a layer of mucus or muco-pus, sometimes slightly mixed with blood. The appearances are most marked towards the pylorus, and sometimes confined to that region.

Under the microscope the blood-vessels in the mucous membrane and especially in the sub-mucous tissue, are found enormously distended and the epithelial cells, both those of the surface and of the glands, enlarged and granular.

Chronic Catarrh

This often remains after one or more attacks of the acute form. It is also present in cases of passive hypenemia of the stomach, which so frequently occurs in consequence of diseases of the heart and liver. Cancer of the stomach is also accompanied by chronic catarrh in most cases.

If the catarrh is prolonged there usually occurs a considerable new-folmation of connective tissue, as in other chronic inflammations. There is thus a thickening which affects mucosa, submueosa, and muscular coat, and causes the surface of the mucous membrane to assume an irregularly folded or warty appearance, which has given rise to the designation Sat mamelonnd. The mucous membrane also presents, in many cases, dark spots or a general deep slaty colour, from the presence of pigment granules in the tissue. The pigment is derived from the blood, and indicates the occurrence of haemorrhages, probably by dia-pedesis. The increase of the connective tissue produces Atrophy of the glands, which are also considerably distorted.

It sometimes happens that the increase of connective tissue is specially great, and the wall of the stomach may be converted into a thick, hard, resistant structure. As all these processes occur mainly in the pyloric portion of the stomach, considerable Narrowing of the orifice may result. The rigidity of the wall and the narrowing of the orifice induce more forcible muscular contractions, and the muscular coat therefore hypertrophies. The thickened and indurated condition may closely resemble scirrhus of the stomach, especially as the muscular coat is-often hypertrophied in that disease also.

Occasionally Mucous polypi develop in connection with chronic catarrh, and these may develop into mucous cysts.

Action of corrosives, caustics, and poisons. Strong acids and alkalies acting on the stomach wall cause necrosis to a greater or less extent, and also produce changes in the resulting slough. As already noted the oesophagus is often but slightly involved. The intestine is-frequently affected, sometimes as far down as the ileo-caecal valve. The intensity of the action depends largely on the concentration of the acid or alkali. Sometimes the whole thickness of the stomach is dissolved, and, the contents having escaped, the action extends to the abdominal organs. The affected parts show various colours, acids generally producing a dark colour, while alkalies lead to a more tawny appearance.

If the patient survive, the sloughs will be discharged, and there may be subsequently cicatricial contraction, leading sometimes to serious deformity and stenosis of the stomach.

Carbolic acid produces a dry, stiff condition of the mucous membrane which has a brownish colour. This condition may also extend to the intestine. (See cases in Western Infirmary Museum).

Arsenic does not produce necrosis, but an irritation, evidenced by hypersemia, and sometimes by ulceration. Decomposition is prevented, by the presence of considerable quantities of arsensic.

Literature

Abercrombie, Researches on dis. of stomach, etc., 3rd ed., 1837; Leube, I.e.; Fenwick, Morbid states of stom., 1868, Atrophy of stom., 1880; Habershon, Observations on dis. of abdom., 3rd ed., 1878; Fox, in Reynold's Syst. of med., 1868; Beaumont, Expers. and observations on gastric juice, etc., 1833 j Silcock, (Phlegmonous infl.) Path, trans., xxxiv., 1883; Leith, Edin. Hosp, Reports, iv., 1896 (with literature).