Examination of the abdomen is an important component of the clinical assessment of anyone presenting with suspected disease of the gastrointestinal tract. As in all other parts of the examination, care must be taken to show respect and concern for the patient while ensuring an appropriate and thorough examination. 

While performing the examination it is useful to keep in mind the concepts of sensitivity and specificity. How confident can we be that a suspected physical finding is in fact present and has clinical significance? For example, how sensitive and specific is our bedside examination for hepatomegaly? What is the clinical significance of an epigastric bruit heard in a thin 20-year-old female versus a 55-year-old hypertensive, obese male? 

In the following sections we will describe an appropriate sequential examination of the abdomen and highlight some of the potential pitfalls of this process. 

Ensure that the abdomen is exposed from the costal margin to symphysis pubis. When describing the location of an abnormality it is useful to divide the abdomen into four quadrants with a perpendicular line through the umbilicus from the xiphoid process to the symphysis pubis. A horizontal line through the umbilicus then allows the abdomen to be divided into 4 areas: the left upper, right upper, left lower and right lower quadrants (Figure 5). On occasion it may be helpful to divide the abdomen into 9 regions with the spaces marked by vertical lines through the left and right mid-clavicular lines and horizontal lines passing through the subcostal margins and anterior iliac crests (Figure 6). 

The overall appearance such as scaphoid, protruberant, or obese should be described, and the location of any surgical scars noted. One should look for any abnormal surface markings, including cutaneous lesions as well as vascular markings. A comment should also be made about the apparent ease of movement of the abdominal wall with respiration and change in body position. Occasionally organomegaly or a mass will be visible. It is helpful to look at the abdomen from the foot of the bed as well. 

It is useful to auscultate the abdomen prior to palpation or percussion, as bowel sounds induced by further examination may mask vascular bruits or pleural rubs. When listening for vascular bruits it is useful to keep in mind the surface markings. The aorta enters the abdomen at or just to the left  of the xiphoid process and bifurcates to the left and right common iliac arteries at the level of the umbilicus. The renal arteries are found approximately one-half the distance between the xiphoid process and the umbilicus, and auscultation is best performed within 2 cm of the midline. Bruits are often best heard at the bifurcation of major vessels; therefore it is also appropriate to listen at the bifurcation of the common iliacs into the internal and external iliacs, approximately halfway between the umbilicus and the inguinal ligament. One should listen over the inguinal ligament for femoral bruits as well. 

A venous hum is best heard overlying the portal vein, which is found in an area approximated by an elliptical shape between the umbilicus and the mid-clavicular line where it crosses the right subcostal margin. Arterial bruits are usually heard only during systole and best heard with the diaphragm of the stethoscope, as they are high pitched. A venous hum is more likely to be continuous and best heard with the bell of the stethoscope, as this is a low-pitched sound. There are, however, no studies to suggest these findings are helpful or reliable in routine examination. Venous hum can occur in portal venous hypertension of any cause. Undifferentiated liver patients in one study had a prevalence of bruits reported as less than 3%. The ability of clinicians to distinguish hepatic arterial bruits from other arterial bruits such as a renal artery bruit has not been studied. 

Friction rubs may occur overlying the liver or spleen and are always abnormal, though rare. Even with careful auscultation of patients with known liver tumors, fewer than 10% are found to have a rub. 

Auscultation for bowel sounds is a rather controversial subject. Bowel sounds should be listened for prior to palpation or percussion, but the yield of this examination is low. The diaphragm of the stethoscope should be placed on the abdomen, as least initially in the right lower quadrant near the ileocecal valve. The particular characteristics of the bowel sounds or even absence of them is not diagnostic of a particular condition, perhaps except for the very high pitched noises of acute small bowel obstruction. In fact, it is probably more helpful in this regard to observe how the bowel sounds change over a period of several hours.  

Palpation of the abdomen should be done in an orderly sequence with the patient in the supine position. Light palpation should be done first in all four quadrants assessing for areas of potential tenderness. Light palpation is a one-handed technique. If no areas of obvious tenderness are elicited, then deep palpation is performed, again in all four quadrants using a two-handed technique. Pressure is applied with one hand over the other hand, which is placed on the abdominal wall, as it is thought that deep palpation with one hand may lead to the inadvertent nonrecognition of suble fullness or mass if the hand applying deep pressure is also responsible for detecting the abnormality. The accuracy of this is untested. It is stated that if a patient has difficulty relaxing the abdominal wall musculature, then placing the soles of the patient’s feet on the bed with hips and knees flexed will aid relaxation; in all likelihood, however, a calm, organized approach with verbal reassurance by the examiner will be just as effective. 

The techniques of palpation of liver and spleen are discussed in Sections 20.5 and 20.6. 

Percussion of the abdomen will detect the presence of bowel gas. The technique as it relates to defining organomegaly and the presence of fluid is discussed in later sections. 

Examination of the liver consists mainly of palpation for the lower edge of the liver and percussion to determine the span. This examination is performed after inspection for right upper quadrant swelling and extrahepatic signs of liver disease. To palpate the lower edge of the liver the examiner starts with gentle pressure in the right lower quadrant of the abdomen. The patient is asked to breathe gently and slowly, in order to bring the liver edge down to the examining fingertips of the right hand. The examiner moves the right hand in a cephalad direction about 2 cm with each breath. If the edge is not felt, no further examination is required. If liver disease is suspected the lower liver edge can be located by percussion. 

If the edge is located, mark the lower border in the mid-clavicular line. Percuss for the upper border starting in the third intercostal space with a finger that is held flat and lies within the space. Move down one interspace at a time until the percussion note changes from resonant to dull. To confirm the change of percussion note strike the third and fourth fingers laid in adjacent interspaces. The note on the top finger should be resonant and on the lower dull. Measure the distance between the upper and lower percussion edges in the mid-clavicular line. Determination of the liver span can be done with firm or gentle percussion to locate the lower border. Gentle percussion is the recommended technique, as this method appears to better estimate liver span as judged by ultrasound. Remember that the upper edge of the liver is dome shaped and not straight across. 

The scratch test has been used to find the lower liver margin. The diaphragm of the stethoscope is placed at the right costal margin in the mid-clavicular line. A finger moves up the abdomen in the mid-clavicular line, scratching gently and with consistent pressure. When the liver edge is reached, there is a sudden increase in the scratching sound heard through the stethoscope. In one comparative study the scratch test was not felt to offer any advantage over the techniques of palpation and percussion. 

When the liver edge is palpable, trace the edge working laterally to medially. Try to determine the characteristics of its surface - for example, soft, firm or nodular. These characteristics may help in the assessment of patients with liver disease; however, agreement about the characteristics is poor, even among experts. Auscultation is rarely helpful. An attempt should be made to assess the left lobe in the epigastrium using these techniques. 

What is the significance of a palpable liver edge? A recent review suggested that a palpable liver is not necessarily enlarged or diseased. When clinical examination is compared to nuclear medicine scanning, about one-half of palpable livers are not enlarged. The inability to feel a liver edge does not rule out hepatomegaly, but does reduce its likelihood. 

What is the normal percussion span? Only one study has been done to establish the normal span. Castell examined 116 healthy subjects using firm percussion. The mean span in the mid-clavicular line was 7 cm in women and 10.5 cm in men. The following nomograms were developed to predict estimated liver dullness in a normal population using firm percussion technique: Male liver dullness equals (0.032 x weight in pounds) + (0.183 x height in inches) - 7.86. The female liver dullness equals (0.027 x weight in pounds) + (0.22 x height in inches) - 10.75. The 95% confidence intervals were ±2.64 cm. Therefore a 5 ft. 10 inch, 175 lb. male would have an estimated liver span of 10.2 cm (range 7.6-12.8) and a 5 ft. 5 inch, 130 lb. female would have an estimated liver span of 7.1 cm (4.5-9.7 cm) by this formula.

The normal spleen is a curved, wedge-shaped organ located beneath the rib cage in the upper left quadrant. The spleen lies beneath the left tenth rib and normally weighs about 150 g, measuring approximately 12 cm in length, 7 cm in width and 3 cm in thickness. The normal spleen usually cannot be palpated, but as it enlarges it descends below the rib cage, across the abdomen toward the right lower quadrant. An enlarged spleen may have a palpable notch along its medial edge. 

Examination of the spleen should begin with observation of the left upper quadrant for an obvious mass, though such a mass is quite uncommon. The examiner should then proceed with percussion over the area of the spleen to look for evidence of dullness, implying splenetic enlargement. The two most useful methods are percussion over Traube’s space and Castell’s sign. 

The surface markings for Traube’s space are the left sixth rib, the left mid-axillary line and the left costal margin. An enlarged spleen may cause dullness over Traube’s space. Percussion should be carried out at one or more levels of Traube’s space from medial to lateral. This maneuver has a sensitivity and specificity between 60 and 70% for splenetic enlargement; however, the sensitivity and specificity increases to approximately 80% in non-obese patients who are fasting. 

Castell’s method involves percussion in the lowest intercostal space in the left anterior axillary line. In normal individuals this area is resonant on percussion and remains resonant on inspiration. In patients with mild splenic enlargement this area will be resonant on percussion and become dull on maximal inspiration. This method has a sensitivity and specificity of approximately 80% for detection of splenic enlargement and would seem particularly suited for detection of a minimally enlarged spleen that may not be palpable. 

Palpation of the spleen should begin in the right lower quadrant and proceed toward the left upper quadrant in order to follow the path of splenic enlargement. Palpation should initially be carried out in the supine position with a bimanual technique using the left hand to gently lift the lowermost portion of the left rib cage anteriorly. The fingertips of the right hand are used to palpate gently for the spleen tip on inspiration. The hand is moved from the right lower quadrant, advancing toward the left upper quadrant. If the spleen is not palpated in the supine position the patient should be moved into the right lateral decubitus position and again with bimanual technique the spleen tip should be sought using the fingertips of the right hand on inspiration. This technique has a sensitivity of about 70% and specificity of 90% for splenic enlargement.

The presence of ascites - free fluid within the abdominal cavity - is always due to an underlying pathological process. Most often the underlying etiology is cirrhosis of any type. Other potential causes include severe right-sided heart failure, lymphatic obstruction, primary intra-abdominal malignancy and  peritoneal metastases. It is easy to identify large-volume ascites clinically, but  the sensitivity of the examination techniques falls with lower volumes of fluid. Ultrasound, which can detect as little as 100 mL of free fluid, is the gold standard against which the clinical diagnostic maneuvers are compared. 

An approach involves inspection for bulging flanks, followed by palpation for the presence or absence of fluid waves combined with percussion to demonstrate flank dullness as well as shifting dullness. One has to be aware that adipose tissue in the flanks may be occasionally mistaken for free fluid. To demonstrate a fluid wave it is necessary to enlist the aid of the patient or another individual. With the patient in the supine position, place one hand on the patient’s flank. With the other hand briskly tap the other flank. A third hand is placed in the mid-abdomen with sufficient pressure applied to dampen any wave that may pass through adipose tissue in the anterior abdominal wall. If fluid is present a shock wave will be felt with the palpating hand. The  sensitivity of this technique is approximately 50% but it has a specificity of greater than 80%. 

When percussing for free fluid one should place the finger parallel to the expected edge and percuss from resonance in the mid-abdomen to dullness in the flanks. This area is then marked and the patient rolled to the opposite side. For example, if flank dullness is demonstrated on the left then the patient should be rolled onto the right side. One should allow approximately 30 seconds for the fluid to move between the mesentery and loops of bowel into the inferior portion of the abdomen. The previous area of dullness in the left flank should now be resonant. It does not matter which side one chooses to start with. In three separate studies shifting dullness had a sensitivity that ranged from 60-88% and a specificity that ranged from 56-90%. 

In one study involving six gastroenterologists and 50 hospitalized alcoholic patients, the overall agreement was 75% for the presence or absence of ascites and reached 95% among senior physicians. 

Interestingly, symptoms are often as useful as physical examination techniques for the clinical diagnosis of ascites. The most useful findings to make a diagnosis of ascites are a positive fluid wave, shifting dullness or peripheral edema. The absence of these findings is useful in ruling out ascites, as is a negative history of ankle swelling or increasing abdominal girth.