Bowel sounds are created when food, bowel gas and feces move through the intestines. Most bowel sounds are normal. On occasion abnormal bowel sounds are heard, indicating the presence of abdominal pathology. Evaluation of bowel activity can be performed by listening to the abdomen with a stethoscope.
When listening to the abdomen with a stethoscope harsh sounds can, at times, be heard. These sounds are called bruits after the French term for noise. The bruits are caused by conversion of the arterial laminar flow to turbulent flow by the presence of atherosclerotic lesions in the blood vessels. When examining the abdomen the area over the aorta, both renal arteries, both iliac arteries and both femoral arteries should be examined carefully for bruits.
Examining the Abdomen
The routine procedure for auscultation of the abdomen is to start at the upper left quadrant and proceed to the upper right, lower right and finally the lower left. Bowel sounds and arterial sounds are high frequency; so use the diaphragm. The same routine should be used for both bowel and arterial sounds.