Inspection of the abdomen is best made in good daylight with the patient in the recumbent posture, but should also be completed by inspection in the standing position. The condition of the skin of the abdomen is first examined. Sometimes striae or scar-like lines running parallel to each other over some part of the abdomen (especially the lower part), and presenting either a silvery hue or, if not old, a rather reddish tinge, are observed; these are always signs of a very marked former distention of the abdominal parietes. Thus they are found after frequent pregnancies, also after the removal of rapidly developing abdominal tumors, or after tapping for ascites. These striae persist long after the disappearance of the conditions which caused their development.

Distention of the abdominal veins, giving them a bluish hue, is observed whenever the return flow of the venous blood of the lower extremities is retarded either by increased intra-abdominal pressure (ascites, tumors of the abdomen) or by thrombosis or compression of the iliac vein or of the vena cava inferior. Cirrhosis of the liver and compression of the portal vein often produce the same result. In the latter condition there is an extensive formation of veins over the navel which is commonly called caput Medusae. After observing the appearance of the skin, the shape of the abdomen is then minutely considered. In normal conditions, in grown people, the abdomen and the chest are on the same level in the recumbent position. In small children the abdomen as a rule is somewhat more prominent than the thorax. In very old age the abdomen appears somewhat sunken. The greatest degree of a retracted or trough-shaped abdomen is found in stricture of the oesophagus or cardia, in basilar meningitis, and in lead poisoning.

Long-continued inanition, no matter of what origin, also causes this phenomenon.

Protrusion of the abdomen occurs either over a definite area or over the entire surface. The abdomen may present the shape of a round hemisphere or of a flattened one if there is an accumulation of air and gas in the intestines (intestinal meteorism). This occurs principally in atonic conditions of the intestines and in hysteria. A uniform protrusion of the abdomen or a general bloated condition is present in general peritonitis, occasionally also in pronounced atony of the intestines. In case of ascites, no matter to what cause it is due (tumors, cirrhosis of the liver, nephritis, etc.), the abdomen is also more or less evenly protuberant above, while the lower parts bulge out somewhat in the recumbent position. This is caused by the accumulation of fluid in the lower portions of the abdominal cavity. Change of posture alters the shape of the abdomen. This applies to the early period of ascites, during which the abdominal cavity is not yet filled to its maximum; later, when this is the case, the abdomen appears uniformly enlarged, and there is no bulging out of any particular portion.

Change of position then no longer alters its shape.

Protrusion of a certain part of the abdomen is noticed in many cases of neoplasm, sometimes in fecal concretions, and occasionally in appendicular abscesses. In umbilical hernia a small, more or less roundish protrusion is noticed in the region of the navel. In diastasis of the rectus abdominis muscles there appears in the middle line of the abdomen a long protrusion of sausage shape consisting of prolapsed intestine. Sometimes there is a pronounced protrusion of this area owing to the escape of a large mass of the bowel through the gap in the muscles.

In patients with thin abdominal walls very small sausage-shaped prominences are occasionally visible which quickly change their configuration, appearing now in one place and now in another. This phenomenon is caused by peristaltic contractions of the small intestine. As a rule, they are not associated with pain and do not denote a morbid condition. Sometimes similar peristaltic waves in the small intestine appear periodically and annoy the patient. Here they may be caused by nervous influences. Peristaltic contractions of the small intestine appearing in a violent manner and caused by a stenosis or an obstruction of the intestinal lumen are usually much more pronounced, that is, the prominences are much higher and involve larger areas. of intestine, the waves moving with greater rapidity and strength and being accompanied by intense pain. Visible peristaltic contractions of the large bowel are ordinarily met with only in cases of partial or total intestinal obstruction.

Inspection of the anal region is best made when the patient lies on his side with his back toward the examiner. The buttocks are held apart with the hands, and thus thorough inspection of the anus is rendered possible. Piles, fissures, fistulae may thus be discovered.

Transillumination

Transillumination of the bowel was first suggested by myself 1 and later practised principally by Heryng and Reichmann.2 After a thorough cleansing of the bowel by means of high irrigation about one quart of water is injected and an electric illuminator (very similar in construction to the gastrodiaphane) is inserted into the rectum. The examination must be made in a dark room. By gradually pushing up the instrument successive portions of the bowel may be transilluminated. This method, however, has not as yet proven to be of any practical value.

Roentgen Bays

The examination of the colon by means of Roentgen rays seems to be somewhat more promising. A soft-rubber rectal tube through which a flexible wire passes is introduced into the bowel as high up as possible and the patient exposed to the Roentgen apparatus. The wire within the tube becomes visible as a shadow, and thus marks the course of the bowel in which it lies. Inasmuch as it is hardly possible to insert an instrument higher up than the sigmoid flexure, the following procedure for the Roentgen examination appears to be of greater value: The bowel is filled with two quarts of water in which 60 gm. (2 ounces) of subnitrate of bismuth are suspended by means of a starch solution. This mixture penetrates almost the entire colon, and thus the position of the large bowel can be determined by the Roentgen rays.

1 Max Einhorn . " Die Gastrodiaphanie. " New-Yorker medicinische Monatsschrift, November, 1889.

2 Heryng und Reichmann . Therapeutische Monatshefte, 1892.