Diagnosis: Do It Well Or Not At All
Medical Author:
Jay W. Marks, MD
During my medical school training, I remember
being counseled by one of my instructors; "In the practice of medicine, it
doesn't matter what you do, it's how you do it." I thought she was being
facetious, and I didn't give her advice much thought. Now, after years of
practice, I understand what she was saying, and the truth of what she said was
reinforced recently.
I was asked by a physician to see a patient in
consultation who had been having episodic abdominal pain every few weeks for at
least five years. She had undergone a hysterectomy (removal of the uterus) followed by
radiation therapy for cancer of the uterus. The pain began a few months after
the radiation. All types of testing had been done, including x-rays
of the small intestine, to
diagnose the cause of the pain but no cause had been identified. Almost in
desperation, she underwent abdominal surgery to remove scar tissue (adhesions) between several loops of the intestines. (Adhesions
often cause abdominal pain.) Even surgery was to no avail, and within two weeks
of the surgery she was having pain again. I was seeing her two years after this
latter surgery.
I took a careful history and examined her. She was a
very good observer and could describe the progression of a typical episode of
pain in detail. To me, it sounded like she was having intermittent obstruction
of the small intestine. Taking x-rays of the small intestine after drinking
barium is one of the best ways of diagnosing intestinal obstruction, and, indeed, she had
such an x-ray prior to her most
recent surgery. The x-ray was sent to me, and I reviewed it. There was nothing
abnormal about it. I asked her if the x-ray was
taken at a time when she was having an episode of pain. It was not.
I then discussed the situation with a radiologist
who had particular expertise and extensive experience with gastrointestinal
x-rays. We arranged for the patient to be seen by the radiologist urgently when
she next developed an episode of pain so that another small intestinal x-ray
could be done. Several weeks later, an episode occurred and the x-ray was
completed. I reviewed it. There was a narrowing of the intestine (medically
known as a stricture, a common cause of obstruction) that was so obvious on the
x-ray that a second year medical student could have made the diagnosis.
Why hadn't the diagnosis been made previously?
The narrowing certainly had been present when the prior x-ray had been done. Why
wasn't it seen? The radiologist and I discussed possible explanations.
During a small intestinal x-ray, patients drink barium, a
substance that blocks x-rays. The intestines fill with barium and appear on x-rays
as a twisting, solid-looking, white tube outlined by "blackness." (The blackness
occurs wherever x-rays do not encounter the barium and instead penetrate
the tissues of the abdomen and reach the x-ray film behind the
patient.) The small intestine is coiled within the abdomen, and loops of
intestine lie on top of one another. X-rays are able to outline the top-most
loop well, but since few or no x-rays penetrate the top-most loops, the deeper
loops cannot be outlined by x-rays. As a result, it may be difficult or
impossible to see the deeper loops.
After patients finish drinking the barium, single
x-ray films of the abdomen are obtained by a technician intermittently (e.g.,
every 15 minutes) until the barium has traveled through the entire small
intestine. This often takes an hour and a half.