CHAPTER 7 Gastrointestinal System^325
Colonoscopy
This test is used to diagnose obstruction, bleeding, change in bowel habits, and
colon cancer, among other conditions. An informed consent is obtained before the
patient is given any type of anesthesia. A colonoscope is passed through the rec-
tum to visualize the anus, sigmoid, descending colon, splenic flexure, transverse
colon, hepatic flexure, ascending colon, and the ileo-cecal valve. The colon may
be insufflated to aid in visualization of the structures. Biopsies are obtained as
indicated. The scope is withdrawn and anesthesia is reversed. The patient may
experience abdominal distention. Risks include perforation of the large intestine.
The test is commonly performed as an outpatient procedure.
Before the test—A thorough colon prep is necessary to ensure complete emp-
tying of the bowel prior to the procedure. The patient is NPO for several hours
prior to the test due to the use of an anesthetic agent.
After the test—Assess the abdomen for bowel sounds and tenderness. Monitor
vital signs. Assess the patient for side effects of anesthesia.
Abdominal Ultrasound
This is a noninvasive test and is usually painless. A transducer is guided over the
abdomen, which produces sound waves that bounce off internal structures and pro-
duce a picture of internal organs and structures.
Before the test—The patient will need to be NPO.
After the test—No special care is needed.Abdominal X-rays
These are plain x-rays, usually flat-plate and upright, of the abdomen, to look for
obstruction, foreign bodies, gas patterns, tumors, and other abnormalities.
Before and after the test—No special care is needed.Liver Biopsy
Here, a small sample of tissue is removed from the liver and examined under a
microscope, allowing for a definite diagnosis. A thin cutting needle, through the
skin of the abdomen, is used to obtain the sample. Needle biopsies are relatively