Most modern units employ adult and pediatric videocolonoscopes, and the general technical specifications for the pediatric instruments differ little between manufacturers (Table 20.4). When and in whom to use a pediatric colonoscope is mainly a matter of personal preference. We use personal judgment based on age and/or body weight. In general terms, the lower limit for the adult colonoscope is 3–4 years of age and/or 12–15 kg. The extra stiffness of the adult versions diminishes the likelihood of forming sigmoid loops, but extra care must then be taken, especially in younger children and with general anesthesia, not to advance against undue resistance, to avoid the unlikely complication of colonic perforation. The larger diameter of the adult colonoscopes can also lead to problems of maneuverability within the smaller colonic lumen of a young child. The variable stiffness colonoscope (see Table 20.4) may negotiate some of these problems. A control dial on the upper shaft of this small-diameter colonoscope (Olympus XCF-240AL/I) allows an increase in the stiffness of the insertion tube when passing through the sigmoid and transverse colon to avoid looping [69].

More recently, magnifying colonoscopes have been developed, and their value in combination with dye spray or chromoscopy in various gastrointestinal diseases has been described [70]. For instance, the decrease in the number of cryptal openings in ulcerative colitis can be observed and correlated to disease activity [71], but this does not substitute for histological assessment.

For insufflation, there may be some advantage awarded by the use of carbon dioxide in place of air because it is more rapidly absorbed, leading to less patient discomfort and, theoretically, less risk of perforation [72, 73].

The patient is usually positioned in the left lateral knee to chest position, although some operators prefer the right lateral position, citing easier sigmoid negotiation. Certainly, if the procedure is not subsequently allowing easy access to the splenic flexure, then patient repositioning from one side to the supine and then to the other side may be advantageous. In general, frequent turning of the patient is conducive to easier ileocolonoscopy as a whole and is to be advocated. An assistant stands on the operator’s left to administer any abdominal pressure that may subsequently be deemed necessary to control, or try to prevent, loop formation in the sigmoid or transverse colon.

One important “trick” in learning ileocolonoscopy is to grasp the concept of the lumen and the positions of a clock face. For instance, if the lumen is at 9 o’clock, then to enter this requires anticlockwise rotation combined with upward deflection of the scope tip from the “neutral” position of 12 o’clock. Similarly, a combination of upward deflection of the tip with clockwise rotation of the colonoscope will allow entry of the lumen, suggested by a dark crescent, if seen at anywhere clockwise from 12 o’clock to 6 o’clock. Obviously, one may equally use downward tip deflection combined with the opposite rotatory control to that with upward tip deflection, and the execution and teaching of this concept are at personal discretion. With either approach, this is the most important maneuver that can be learned to assist in three-dimensional spatial orientation in the colon.

Prolonged “side viewing” of the bowel wall as it slides by should be avoided. Generally, the only place where, very temporarily, the lumen should be out of view is the occasional difficult negotiation of the splenic flexure. The patient’s position may be changed throughout the procedure to facilitate removal of loops and to allow a better view of the lumen because the gravity-dependent material in the colonic lumen changes position. Relatively minimal insufflation of air is desirable in the sigmoid colon because excess air may increase the chance of sigmoid loop formation (carbon dioxide provided by a specific commercially available delivery system attached to the colonoscope may be preferable because it is absorbed much more quickly decreasing pain and the very unlikely chance of perforation; see “Complications”).

In handling the colonoscope, it is good practice to have a flat unimpeded surface on which to place the remainder of the colonoscope that is not yet inserted; this is particularly important since any resistance encountered by the operator to forward advancement of the colonoscope can be attributed to colonic obstruction or loop formation within the child’s colon. Hence, relatively quickly, the trainee can acquire a realization of the normal expected resistance to scope advancement. This, in turn, allows understanding of the likelihood of loop formation, without any external resistance to scope advancement, causing confusion with regard to the behavior of the colonoscope within the patient.

Generally, in ileocolonoscopy, gentle scope advancement with clear lumen visualization is desirable, and, usually, only the forefinger and thumb will be required to advance the colonoscope. If greater pressure is required, then the operator is not performing an optimum procedure, and loop formation is likely to have occurred.

Prior to any colonoscopy, it is considered good practice to perform an anal and then a rectal digital examination, the latter to avoid missing, by colonoscopy, very low-lying rectal polyps (although, where possible, retroflexion of the colonoscope in the rectum should occur prior to removal of the instrument to avoid missing lesions close to the anal margin). Adequate water-soluble lubrication, avoiding the tip of the instrument, allows easy passage into the rectum, which can occur with or without digital guidance from the operator’s index finger. Posterior positioning of the tip and air insufflation will allow visualization of the rectal mucosa and the three semilunar folds, or valves of Houston, occurring on alternating sides of the lumen. Subsequently, direct visualization of the bowel lumen is mandatory, except in some circumstances at the splenic flexure. If, at any point, a maneuver results in loss of visualization of the lumen, then reversal of what the operator has just done will often return the lumen to view; if not, the gentle scope retraction combined with minor tip deflections using the wheels and minor rotation of the scope in both directions will usually result in reorientation in the lumen. Obviously, if luminal contents are blocking the view, then lens cleaning will help.

Gentle torquing of the shaft clockwise and anticlockwise combined with upward or downward tip deflection and scope advancement is ideal for negotiating the sigmoid colon—the so-called “torque-steering” technique. The initial sigmoid fold or valve can usually be passed by 90–120 of anticlockwise torsion. The different loops encountered in the sigmoid are demonstrated in Fig. 20.3. A so-called N loop may be overcome by trans-abdominal pressure by an assistant on the apex of the loop pushing toward the feet (see Fig. 20.3a). This often allows a so-called α loop to form, which can usually be tolerated as the instrument advances toward the splenic flexure (see Fig. 20.3b). Reducing an α loop is accomplished by initial clockwise rotation and then slow removal of the colonoscope, keeping the lumen in the center of the field of vision. This may not be possible until the transverse (or even ascending) colon has been entered, in which case, hooking the tip of the scope over the splenic flexure may assist it. Paradoxical movement of the tip forward may be observed as the instrument is withdrawn and the bowel “concertinas” over the colonoscope. Abdominal pressure in the left iliac fossa may be helpful. The sigmoid and descending colons are relatively featureless, with less haustral folds than more proximally in the colon.

Nonlooped colonoscope length used at this point might be 40 cm in older children and even 20–25 cm in those under the age of 3–4 years. This is valuable in determining whether a loop is present. At the splenic flexure, the spleen may then be seen as a dark blue transmural discoloration. When negotiating the splenic flexure, the most successful combination of tip maneuvers is that of clockwise, right, and up followed by anticlockwise after passing the flexure. Occasionally, placing the patient in the right decubitus position may assist. The transverse colon is recognized by the triangular haustral folds and is usually easily passed (Fig. 20.4). Supine or right decubitus positioning may ease this. A loop in the shape of a “U” may occur in a dependent transverse colon, which is supported by abdominal pressure. The more difficult γ loop may occur in a redundant transverse colon (Fig. 20.3c). In addition, a good bit of advice is to apply gentle suction as the tip is advanced again in an attempt to concertina a potentially long dependent transverse colon over the colonoscope, thus maintaining a relatively short colonoscope and, hence, good control and maneuverability.

Nonlooped colonoscope length used at this point might be 60 cm in older children and even 40 cm in those under the age of 3–4 years. This is valuable in determining whether a loop is present. The hepatic flexure is also recognized by the dark, usually blue, discoloration seen through the bowel wall, and positional change to the supine or right decubitus may again facilitate identification of the lumen. The combination of right, up, and clockwise followed by anticlockwise rotation and suction down into the ascending colon once around the sharply angled hepatic flexure is usually the most effective maneuver, but various combinations, including position change and scope withdrawal, may be required. Another tip is to remember that it is easy to be too far advanced into the vault of the hepatic flexure, leading to advance into a blind end, and often slight withdrawal of the instrument may reveal the fact that one is trying to negotiate this blind-ended area. The two or three sharp folds then observed may then be most successfully negotiated by tip deflection using both up/down and left/right wheels with minimal advancement of the scope. This is most easily performed in the supine patient position, however.

Once the hepatic flexure is negotiated, the transverse colonic γ loop may be reduced with anticlockwise or clockwise rotation followed by withdrawal of the colonoscope and suction. Loop withdrawal is essentially informed guesswork initially. Studies with the colon Map guider, based on using a colonoscope with an inbuilt electromagnetic loop that allows accurate real-time colonoscope three-dimensional positioning by detection using an external positioning device and displayed on a screen next to the patient, have shown that even expert colonoscopists get the type of loop present wrong in half of the cases [74–76]. Once one starts to remove the loop, using rotation only initially, a tip is to gently start to remove the colonoscope and try to determine whether within-patient resistance is increasing or whether the colonoscope is trying to push your hand away from the patient as the loop unfolds. Usually, trying clockwise or anticlockwise combined with instrument withdrawal will, with experience, allow early determination of which rotation direction is likely to be successful in “delooping” the colonoscope. It is best to try to maintain good luminal vision during this procedure, but, not infrequently, the lumen is lost; however, if this loop removal technique is effective, it is then not unusual to find oneself then looking at the appendiceal orifice and hence the cecum because the scope will have naturally traveled down the ascending colon. It is important to remember that the ascending colon, which in children is of variable length, may be as short as 5 cm in some younger patients.

Three useful ways to ensure that one has reached the cecum are as follows:

A good maxim is that if there is any doubt in the operator’s mind about having reached the cecum, then one is usually at the hepatic or even splenic flexure. Only about 80 cm of scope from the anus is needed when all loops are removed in an adult, and in smaller children, only 40–60 cm may be needed. This assumes normal anatomy of the ascending colon and cecum. Obviously, cecal strictures can confuse the picture.

The ileocecal valve is present approximately 1–4 cm distal to the appendiceal orifice opening into a smooth asymmetric fold and opens perpendicular to the axis of the colon. Figure 20.5 shows the steps of the easiest technique for ileal intubation. Removal of any colonic loops is important to allow for a responsive scope with no paradoxical movement. Figures 20.5b and 20.6 show the valve maneuvered to the 6 o’clock position, usually after clockwise rotation of the scope and wheel-tip deflection to maintain a centered cecal view. Anticlockwise rotation can also be used but is less efficient. If too much gas is present, then the cecum may be “tented,” and this should be suctioned prior to an ileal intubation attempt. Figures 20.5c and 20.7 show the insertion of the biopsy forceps such that just the tip or the first few millimeters are visibly exposed beyond the end of the scope. The scope is then inserted just beyond the fold (using the downward deflecting wheel with the scope as above already in the 6 o’clock position), and the tip is inclined downward so that the forceps gently press into the wall. Slight left inclination may be required at this point to open the valve like a pair of lips on slight withdrawal of the scope (Fig. 20.5c). Once the valve is opened, the scope may be passed into the ileum with further downward deflection. Often this is facilitated by small right and left deflections with an assistant pressing on the abdomen over the transverse colon to support a dependent transverse and also prevent loop formation. In the absence of ileocecal valve strictures, and with practice, this technique will allow an ileal intubation rate of 100%. Perforation of the cecum or ileum with this technique is a theoretical concern raised by some observers unfamiliar with this technique, but this has not occurred in our experience of over 5,000 ileocolonoscopies and is extremely unlikely.

An alternative technique is “blind” intubation of the ileocecal valve. This involves the same positioning of the valve at 6 or 9 o’clock and then slowly withdrawing the scope back from just beyond the valve’s fold while insufflating with air and deflecting the scope tip downward. The disadvantage of this technique is that it is not under direct vision.

The ileal mucosa will have the typical velvet-like appearance of small bowel (Fig. 20.8), with the presence of smoother raised areas, which are Peyer patches, and, occasionally, lymphonodular hyperplasia of varying degrees (Fig. 20.9). Villi are more easily seen if the lumen is flooded with water. The ileal surface is shown in greater relief with a spray of standard blue or black ink (methylene blue in a 1:20 dilution may also be used); this is also useful in showing the detail of sessile polyps in the colon. Deeper intubation of the ileum by either technique is similar to duodenal negotiation during upper gastrointestinal endoscopy, and up to 40 cm of ileum can be observed.

It is pertinent here to discuss the diagnostic need for entering the ileum in children suspected of IBD. Williams et al., in 1982 [77], reported their experience of total ileocolonoscopy in children in which the terminal ileum was examined in 63 patients. In six children, ileitis detected by ileocolonoscopy was the sole finding of Crohn disease, which was previously unrecognized by radiological contrast studies. Lipson et al. compared ileoscopy and barium studies, with an endoscopy specificity of 0.96 for diagnosis of Crohn disease in the terminal ileum [78]. In 14 of 46 children, ileoscopy revealed diagnosis, which would otherwise have been missed. This study also made clear that the endoscopic appearances could be completely normal, yet the diagnosis of Crohn disease could be made histologically by the presence of granulomata. Also, a pronounced lymphoid hyperplasia pattern was present radiologically in 24% of children and would have been a source of error in two cases had contrast radiographs been relied on to make the diagnosis without ileoscopy. More recently, Deere et al. showed that sigmoid, colonic, and rectal biopsies confirm the diagnosis of IBD in only 60% of cases, and diagnosis based on morphological criteria was possible in only 85% of cases when the cecum was reached without ileal intubation [79]. Geboes et al. assessed 300 patients, including adolescents and children, and found endoscopic and histological ileal lesions in 123 and 125, respectively, of whom no colonic disease was present in 44 [80]. Ileal biopsies were essential for the diagnosis in 15 patients and contributory in 53. There are, of course, other reasons apart from the principal one, that is, diagnosis of chronic IBD, for entering the ileum in children. For instance, ileoscopy will facilitate diagnoses of other causes of ileitis such as infection with tuberculosis or Yersinia [81]. In addition, therapeutic dilation of short terminal ileal strictures by per endoscopic balloon catheter may be attempted.

A more careful inspection of the colon is necessary on withdrawal of the scope, especially for the presence of polyps, which may have remained hidden behind a haustral fold during the initial insertion of the scope. Biopsies should be taken from all areas, including normal-looking mucosa to allow for accurate histological diagnosis. Biopsy technique is similar to EGD, with the exception that many colonoscopic biopsy forceps have a central barb, allowing more than one biopsy to be taken each time the forceps are passed.

Lastly, before removing the scope from the anus, a retroflexion maneuver obtained by maximum upward and right or left tip deflection and slight advancement of the scope into the rectal vault, followed by rotation clockwise and anticlockwise through 180° completes the examination. This is necessary to observe the ano-rectal junction and distal rectum. Distal ulcers, inflammation, or even polyps can be missed if this is not done.

Through-the-scope balloon dilators are appropriate for ileocolonic dilation, employing the same concept and method as for upper gastrointestinal strictures, employing radiological screening control. Long-term symptomatic relief can be afforded in some carefully selected patients, including adolescents in reported studies [82, 83]. Pressures of 35–50 psi in balloons of 12–18 mm are available. Theoretically, as for neoplastic or diverticulitis-associated strictures in adults, stent placement could be used as a last resort in IBD-type strictures, but there are no reported cases of this occurring in childhood as yet.