Practical Gastrointestinal Endoscopy

COLONOSCOPY AND FLEXIBLE SIGMOIDOSCOPY 165
be remarkably long, however, and full bowel preparation is
essential. Colostomy washouts are less effective. The first few
centimeters through the abdominal wall and proximal to the
colostomy are sometimes awkward to negotiate and to examine,
partly because of the continual escape of insufflated air. If there
is a loop colostomy the afferent and efferent (proximal and distal)
sides can be examined.
Pelvic ileo-anal pouches are easy to examine with a standard
instrument. Limited examination of an ileal conduit is possible,
using a pediatric endoscope (colonoscope or gastroscope).
PEDIATRIC COLONOSCOPY
Pediatric colonoscopy, from neonatal to 3–5 years of age, is best
performed with a thinner (1·cm), preferably ‘floppy’, pediatric
colonoscope. In older children, depending on physique, adult
colonoscopes can be used, and for teenagers they are mandatory.
The infant anus will accept an adult little finger and so will
take an endoscope of the same size. The neonatal sphincter first
requires gentle dilation over a minute or two, using any small
smooth tube (such as a nasogastric tube or a ballpoint pen cover).
The main advantage of a purpose-built pediatric colonoscope is
more the extra flexibility or ‘softness’ of its shaft than its small
diameter, because it is easy with stiffer adult colonoscopes to
overstretch the mobile and elastic loops of a child’s colon. It is
generally a mistake to use a pediatric gastroscope for anything
but a very limited inspection because it is much stiffer. An adult
13–15·mm colonoscope, although usable, is nonetheless too
clumsy to be ideal in the colon of a small child—reminiscent of
driving a large articulated truck through small alleyways—uncomfortable
for all concerned.
Who should perform pediatric colonoscopy is a matter of local
judgment. Few pediatricians do enough colonoscopy to become
really dextrous. If complete colonoscopy is required it may often
be best for examination to be by a skilled adult endoscopist, with
the pediatrician present.
Bowel preparation in children is usually very effective. Pleasanttasting
oral solutions such as senna syrup or magnesium citrate
are best tolerated. A saline enema will cleanse most of the colon
of a baby.
General anesthesia is frequently used, although children of any
age can be colonoscoped without general anesthesia providing
that the endoscopist is experienced. Reasonable intravenous
medication is used, but a pediatrician with experience of resuscitation
must be present as a safeguard. A suitable oral sedative
premedication (such as antihistamine or pethidine) can be
useful so that a particularly anxious child is relaxed before the
procedure. A small dose of intravenous (IV) benzodiazepine (Diazemuls®
2–5·mg or midazolam 1–3·mg) is usually combined