Author’s replyBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d3960 (Published 28 June 2011) Cite this as: BMJ 2011;342:d3960
All rapid responses
I think Dr Spence has fallen into a trap and assumed that digital
rectal examination (DRE or PR) is just for examining the rectum. For years
I have held the view that many people carrying out a digital examination
of the rectum only do part of what is possible for this examination. The
lubricated finger once inserted into the anal orifice has to pass through
the anal canal before it reaches the rectum and much information can be
obtained about this anatomical structure before (and maybe after) the
rectum has been examined. I fear, however, that too many people carrying
out a DRE are so relieved they have found the correct orifice and that
they are actually in the rectum that they forget to examine the anal
Palpation of the outer part of the anal canal can reveal tenderness,
swellings and defects. Once in the anal canal the resting pressure (an
index of internal sphincter function) can immediately be evaluated, the
length of the anal canal and the anorectal angle can be assessed. By
simply asking the patient to tighten up their back passage the squeeze
pressure (an index of external sphincter function) can be evaluated. I
personally believe that with a little sideways pressure of the dorsum of
the finger on the anal canal the finger pulp can be used to palpate
haemorrhoids. Over and above these findings tenderness, swellings and
defects can be felt within the anal canal. So there is much to examine in
the anal canal and useful physiological and anatomical information can be
When I teach trainees how to do a DRE I first try to impress on them
that there is more to the examination than finding out what might be going
on in the lower part of the rectum and then I attempt to convince them
that the name of the examination should be digital examination of the anal
canal and rectum (DEACR).
The information we derive from this part of routine physical
examination will often be normal and should be recorded as such; then when
in the future a patient comes with anal canal problems or dysfunction the
baseline data will be available.
Dr Spence may be correct that it is not good medicine to insert an
examining finger into every rectum to ensure we do not miss rectal cancers
and prostate problems, but before we confine this examination to the waste
bin we must be sure we know what information the examination is capable of
yielding as otherwise we could be accused of "flimsy thinking". Rather
than abandoning DRE let's try doing the examination properly and calling
it by a proper name - digital examination of the anal canal and rectum -
Competing interests: No competing interests
Dear Dr Spence,
You have certainly been successful in raising the debate!
Beyond a friendly introduction and a handshake, pretty much nothing
in medicine is technically routine - ie you need a reason to do it. So to
say a PR examination shouldn't be done 'routinely' in for example surgical
and geriatric patients is, for me, technically correct.
In most primary care it sounds as though this broadly holds true, in
that it doesn't directly affect your management. If a patient needs more
investigation on the basis of the history and the examination isn't going
to change anything- what's the point?
However in the secondary care population, especially the acutely
unwell, there is important (and often unexpected) information to be gained
from doing a PR- not least an objective assessment of a patient's stool.
In addition, aside from some discomfort, there is little cost in such an
examination. (I feel it is less "unpleasant and invasive" than a blood
test) The threshold for doing a PR therefore is very low.
So low that consultants often expect it to be done routinely to avoid
important information being missed by inexperienced juniors who have been
told in their medical education that "this is a bit of a pointless
Secondly I don't think an examination such as a PR has to be
diagnostic to be worth doing. Most of our examination is not diagnostic
(it is not even designed to be), so why have a different rule for a PR?
A patient's reporting of any of their symptoms is a reflection of
their previous experiences. An important part of what we do is trying to
make objective assessments of patients symptoms. A thorough examination
inc a PR aids us in this and helps us form a differential to guide on-
For both these reasons a PR has become routine in some areas of
secondary care and hopefully will remain so. I can see how from a primary
care perspective, it is less useful.
Approaching our examination like a screening test is an interesting
idea. It would seem obvious that an examination with poor sensitivity and
specificity isn't worth doing. However we don't use any examination (inc
PR) in isolation. As I said above we amalgamate our examination findings
with the history to generate a differential and guide investigation. Is
there not also a qualitative aspect to examination findings that can't be
captured in a ROC curve?
For these reasons I think examination 'tests' are fundamentally
different from surrogate markers of disease such as PSA used in screening.
While we should be aware of the limitations of examination we should not
approach it in the same way.
Even with advances in medical diagnostics nothing should take the
place of a thorough examination, as this is the most direct assessment of
a patient we have.
Competing interests: No competing interests