Practical Gastrointestinal Endoscopy

COLONOSCOPY AND FLEXIBLE SIGMOIDOSCOPY 91
Bowel preparation
A doctor, nurse or other informed team member should talk to
the patient at the time of booking to explain the procedure, and
the importance of successful bowel preparation. Most people
who haven’t had colonoscopy subsequently admit that the anticipation
of it, including fear of indignity, of a painful experience
or the possible findings, is worse than the reality of the procedure
itself. Anything that will justifiably cheer them up beforehand,
whilst ensuring understanding and also compliance with dietary
modification and bowel preparation, is extremely worthwhile.
Minutes spent in explanation and motivation may prevent
a prolonged, unpleasant and inaccurate examination due to bad
preparation. The patient needs to know that a properly prepared
colon looks as clean and easy to examine as the mouth—whereas
poor preparation leads to a degradingly unpleasant and inaccurate
examination.
Limited preparation
Enemas alone are usually effective for limited colonoscopy or
flexible sigmoidoscopy in the ‘normal’ colon. The patient need
not diet and typically has one or two disposable phosphate
enemas (e.g. Fleet Phospho-soda®, Fletchers’, Microlax), selfadministered
or given by nursing staff. Examination can be
performed shortly after evacuation occurs—usually within
10–15 ·minutes—so that there is no time for more proximal bowel
contents to descend. The colon can often be perfectly prepared to
the transverse colon in younger subjects (in babies phosphate enemas
are contraindicated because of the risk of phosphatemia).
Note that patients with any tendency to faint or with functional
bowel symptoms (pain, flatulence, etc.) are more likely to have
severe vasovagal problems after phosphate enemas; make sure
they are supervised or have a call button, and that lavatory doors
open from and towards the outside in case the patient should
faint against the door.
Diverticular disease or stricturing require full bowel preparation
even for a limited examination, because bowel preparation
will be less effective and phosphate enemas less likely to work.
If obstruction is a possibility, peroral preparation is dangerous,
even potentially fatal. In ileus or pseudo-obstruction,
normal preparation simply does not work. One or more largevolume
enemas are administered in such circumstances (up to 1
liter or more can be held by most colons). A contact laxative such
as oxyphenisatin (300·mg) or a dose of bisacodyl can be added to
the enema to improve evacuation (see below).