Practical Gastrointestinal Endoscopy

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CHAPTER 6
(a) (b) (c)
Fig. 6.91–Entering the ileo-cecal valve. (a) Distant view of the valve
slit. (b) Pushing in directly impacts against upper lip. (c) Overshooting
the valve a little lets the tip angle-in successfully.
submucosal vascular pattern. After colon resection the difference
between colon and ileum may be imperceptible because
of villus atrophy. Using the dye spray technique—0.1% indigo
carmine, 5% methylene blue (which stains) or 1·:·4 dilution of
washable blue (ink)—to highlight the surface detail will rapidly
discriminate between the granular or ‘sandpaper’ appearance
of the ileal mucosa and the small circumferential grooves of the
colonic surface, which give a ‘fingerprint’ effect.
The ileum is soft, peristaltic and collapsible compared to the
colon, and should be handled more like the duodenum. Rather
than attempting forceful insertion, greater distances can be travelled
by gentle steering and deflation—so that the intestine collapses
over the colonoscope. At each acute bend it is best to deflate
a little, hook round, pull back and then steer gently (if necessary
almost blindly) around and inward before pulling back again to
relocate the direction of view—the ‘two steps forward and one
step back’ approach that applies throughout colonoscopy. When
the colonoscope tip is in the ileum, it can often be passed for up
to 30–50·cm with care and patience, although this length of intestine
may be folded on to only about 20·cm of instrument. Air
distension in the small intestine should be kept to a minimum
because it is particularly uncomfortable and slow to clear after
examination—another reason for routinely using CO 2
.
EXAMINATION OF THE COLON
Better views are obtained overall during withdrawal than on insertion,
so more painstaking examination is usually performed