A general examination is performed, with particular emphasis on the examination of all lymph nodes and noting the presence of anaemia or jaundice. Detailed examination of the gastrointestinal tract starts with the mouth and tongue, before examining the abdomen with the patient lying flat.

Examination of Abdomen

Inspection

Abdominal distension, whether due to flatus, fat, fetus, fluid or faeces, must be looked for. Lordosis may give the appearance of a distended abdomen; it is a common feature of the ‘abdominal distension’ seen in functional bowel disorders.

Palpation

The abdominal organs may be felt in some normal subjects but this is not common and such organs are usually only just palpable. A Reidel’s lobe is an extension of the lateral portion of the right lobe of the liver and can occasionally be palpated.

Any palpable mass is carefully felt to decide which organ is involved and also to evaluate its size, shape and consistency and whether it moves with respiration. The hernial orifices should be examined if intestinal obstruction is suspected.

A succussion splash suggests gastric outlet obstruction if the patient has not drunk for 2-3 hours; the splash of fluid in the stomach can be heard with a stethoscope laid on the abdomen when the patient is moved.

Percussion

This is performed in the usual way to detect the area of dullness caused by the liver and spleen, and possibly bladder enlargement. The presence of fluid in the peritoneal cavity (i.e. ascites) is detected by shifting dullness. The percussion note changes from resonance to dullness when the patient is moved from one side to the other. It is a good physical sign, but 1-2 L of fluid must be present to elicit it. A large ovarian cyst can sometimes produce an enlarged abdomen, but the dullness is more centrally placed than in ascites.

Auscultation

Auscultation is not of great value in gastrointestinal disease, apart from in the evaluation of the acute abdomen. Abdominal bruits are often present in normal subjects, but these are not clinically significant.

This is the term used to describe excessive wind. It includes belching, abdominal distension, ‘wind’ or the passage of flatus per rectum. Swallowing air (aerophagia) is described later on. Some of the swallowed air is passed into the intestine where most of it is absorbed. Intestinal bacterial breakdown of food also produces a small amount of gas. Flatus consists of nitrogen, carbon dioxide, hydrogen and methane. Flatus is normally passed 13-20 times per day.