So now let's go to a case.
A 63-year old woman presents to the emergency
department complaining of progressive abdominal pain,
nausea and vomiting for the past 2 days.
She has not passed a bowel movement
for 5 days and is not passing gas.
Her surgical history includes a prior exploratory
laparotomy for a gunshot wound.
Vitals are significant for a heart
rate of 110 but otherwise normal.
On exam, she has hyperactive bowel
sounds, moderate tenderness to palpation
and no rebound tenderness or guarding
So, what is the best next diagnostic test?
Let's point out some key features.
She has abdominal pain, nausea and vomiting and
the absence of passing gas and bowel movements
She does have a history of abdominal surgery
and her physical exam is notable
for hyperactive bowel sounds.
So, the first question is, what is the
significance of her obstipation?
Obstipation is the term we use to describe the lack
of passing flatus or gas in addition to constipation.
This is a very concerning
symptom for a bowel obstruction.
So, let's talk a bit about
small bowel obstructions
We can categorize SBO's into
partial or complete obstructions.
In partial SBO's, patients are able to
pass gas or have small bowel movements.
But in complete obstruction,
they have complete obstipation.
Some common causes are from
adhesions from prior surgeries,
they may have incarcerated hernias,
cancer or history of
inflammatory bowel disease.
Patients will present with crampy abdominal pain,
nausea or vomiting, or the presence of obstipation.
The diagnosis of a small bowel
obstruction is made by abdominal x-ray.
So here, you could see an example of an x-ray
from a patient with an SBO.
The typical features you will see are:
dilated loops of small bowel, as shown
here and the presence of air-fluid levels
so those are horizontal cutoffs between
areas of air which appears dark on the x-ray
and areas of fluid which
appears white on the x-ray.
The treatment of an SBO depends
whether it is partial or complete.
If it is a partial obstruction, in most cases, we
can treat with IV fluids, allowing for bowel rest
and inserting a nasogastric
tube for decompression.
If the patient has a complete
obstruction, this usually requires surgery.
So now we can return to our case.
Our 63-year old woman presenting with
abdominal pain, nausea, vomiting and obstipation
with history of abdominal surgery
and hyperactive bowel sounds.
So the important clues here
are that she has acute obstipation
and her hyperactive bowel
sounds indicate a likely obstruction.
So now we know the best next diagnostic test
is an abdominal x-ray, also known as a KUB.