Indications:

1. To prevent post polypectomy bleeding (particularly with large stalked polyps) or for treatment of post polypectomy bleeding
2. Also used to prevent bleeding in gastric polypectomy

Steps:

1. The endoloop comes preloaded, attached to the end of the sheath
2. The loop will be protected in a plastic casing, from which it needs to be taken out
3. The handle has got a yellow bung, a thumb ring and a body (where index and middle fingers rest) of the handle.

Picture1: The handle of the endoloop

1. Pushing the yellow bung away from the handle (step1) will bring the loop inside the sheath

Picture2: Step1- ensheathing the loop before passing through the channel

1. Next the sheathed loop is fed through the accessory channel
2. Once polyp is located, loop is opened out of the sheath by pulling the yellow bung towards the handle ( Step2-reverse movement of step 1)

Picture3: Step2-Reverse movement of step 1- bringing the loop out of the sheath

1. The loop is then placed over the polyp or the polypectomy stalk
2. The loop is then tightened over the stalk – by closing the handle (i.e. the index and middle finger will close in to the thumb) Step3 – which moves a silicone stopper to close the loop. Don’t close too tightly; otherwise it might snare the polyp off.

Picture4: Step 3- tightening the loop

1. Once tight – check for blanching around the loop as a result of restricted blood flow
2. Lastly to fire/detach/deploy the loop- open the handle fully (Step 4- reverse movement of step 3)

Picture5: Step 4- Reverse of step3- firing/detaching the loop

1. Loop usually stays in for up to 7days and then falls off

Video link of how to use endoloop

1. Indigo carmine-
   • It pools in crevices between epithelial cells thereby highlighting small or flat lesions and defining irregularities in mucosal architecture.
   • It is used to
   • To assist in detection of dysplastic changes in patients with ulcerative colitis undergoing surveillance colonoscopy.
   • To assist in detection of adenomas in patients with hereditary nonpolyposis colorectal cancer.
   • To diagnose small gastric cancers
2. Methylene blue

Methylene blue is absorbed by actively absorbing tissue like small and large intestinal epithelium, staining them blue. It does not stain nonabsorptive epithelium like squamous or gastric epithelium.
The most extensive experience with methylene blue has been in the evaluation of Barrett’s oesophagus. Barrett’s oesophagus stains diffusely with methylene blue because of the specialised columnar epithelium. Dysplasia/carcinoma is associated with focal areas of decreased stain intensity and/or increased stain heterogeneity due to the differential absorption of methylene blue dye into dysplastic cells that have varying degrees of goblet cell loss. Thus, abnormal methylene blue staining is helpful in delineating dysplastic or malignant areas for diagnosis and endoscopic therapy, if needed.
Recently concerns has been raised regarding the potential to induce oxidative damage to DNA (and hence accelerate carcinogenesis) in tissues exposed to methylene plus white light (such as during endoscopy).  However, this theoretical risk for increasing neoplastic transformation has not been proven by clinical studies.

Current status

Although NBI is already commercially available, the classification of mucosal and vascular patterns with NBI is not yet standardized and validated. Thus, additional studies are needed before it can be incorporated into routine clinical practice. The combination of the mucosal and vascular pattern may ultimately prove to be an accurate endoscopic tool that can help in increased detection of abnormal areas and targeted biopsies of areas with suspicious superficial morphology.

• The ileo-caecal valve is the only definite anatomical landmark in the colon. It may occasionally be difficult to find
• The internal appearance of transverse colon is usually triangular. However the descending colon may look triangular or the transverse colon may look circular
• There may be bluish/grey indentation from the liver at the hepatic flexure; however a similar appearance may sometimes occur at the splenic flexure.
• The distance of the lesion should only be mentioned on withdrawal. So you could say that the lesion/polyp was at 30cms in the sigmoid colon on withdrawal. The scope distance information at insertion is meaningless due to the elasticity of the colon
• For the above difficulties of localisation, any area which may need repeat inspection or treatment should be tattooed.

Lesion recognition

• Normal colonic mucosa shows a fine, ramifying vascular pattern.
• Mucosal lesions- The vascular pattern is lost in marked hyperaemia as in IBD.
• There are 9 different endoscopic indices of activity for ulcerative colitis (UC) developed for clinical trials; none have been validated. All 9 indices are subject to interobserver variation (IOV).
• Feagen score for assessing severity of colitis
  Stage 1- Granular, hyperaemic mucosa, vascular pattern not visible, not friable
  Stage 2- above plus friability (bleeds on contact, but not spontaneously)
  Stage 3- above plus spontaneously bleeding
  Stage 4- Above plus clear ulceration
  Whenever describing a colitis mention at least the extent, whether circumferential or not, friability and presence of ulceration.
• The typical endoscopic features of Crohn’s disease are the discontinuos spread of the disease, lesions are distributed asymmetrically. There may be bizarre, ‘map-like’ necroses and fissures. Appearances of so called ‘snail tracks’, aphthoid ulcers etc
• Malignant polyp- is suspected if the polyp is irregular, ulcerated or thick walled. Firmness to palpation with a snare tube is probably the best discriminant for a malignant polyp. If malignancy is suspected, transect low in the stalk and tattoo the area.
• Carcinomas are usually obvious.
• Pseudomembranous colitis- typical membrane like deposits.

• Strictures more than 5 cms in length should not be balloon dilated.
• Dilate only fibrotic strictures without ulcer.
• Dilate only if symptomatic.
• Malignant stricture- never dilate

Remember:

• One or more session may be needed. Alternatively, the stricture can be dilated once and if symptoms recur- they can be dilated again.
• The technical success rate, defined as achieving an endoscopically passable residual stricture, is between 70% and 90 %, independent of the balloon’s diameter.
• Complications such as haemorrhages are rare, while perforations are reported mostly in studies in which 25 mm balloons are used.
• It is difficult to define the relapse risk after endoscopic balloon dilatation, as the published studies are heterogenous. In a recent long-term study, stricture relapse rate was 46% after a mean of 32 months. (Stienecker K. Long-term results of endoscopic balloon dilatation of lower gastrointestinal tract strictures in Crohn’s disease: a prospective study. World J Gastroenterol.2009 Jun 7;15(21):2623-7)

Size of balloon
If the stenosis  is > 5mm in diameter- use 18-20 mm balloon
If the stenosis  is < 5mm in diameter- use 15 mm balloon
Pinhole stenosis- 12 mm balloon

Colorectal stent
Indications

• Palliative decompression of advanced disease
• Preoperative decompression- stent insertion avoids an emergency surgery with its benefit on morbidity and mortality

Types of Stent

• Through the scope stents- inserted under direct vision
• Inserted over a guidewire under fluoroscopic guidance

Complications
The major complications are stent migration (11 percent), perforation (4.5 percent), and reobstruction (12 percent).

• Essentially all mucosally based pedunculated polyps can be removed endoscopically.
• Patients with sessile polyps <2 cm in size can be resected in most cases.
• Many sessile polyps >2 cm in size are also resectable endoscopically depending on their location within the colon.
• As a rule of thumb, it has been suggested that sessile polyps occupying more than one-third of the colon circumference, or involving two haustral folds, are too big for safe endoscopic removal.

Diathermy current

• Electrosurgical or diathermy currents cause heat, thus coagulating local blood vessels. This current is very high frequency and thus produces heat but no shock. This is because there is no time for muscle and nerve membrane depolarisation before the current alternates again and therefore no muscle contraction or afferent nerve impulse (contrast low frequency household currents).
• Modern cardiac pacemakers are unaffected by the relatively low power used for endoscopic electrocautery.
• Monopolar diathermy is used in endoscopy.  The principle is the concentration of current at the active electrode (endoscopic accessory) with a small surface area, concentrating the heat at the operative site. The larger return plate (patient plate), which completes the circuit, spreads the current over a wide area so that it is less concentrated and thus produces little heat.
• Types of current- Cutting current have an uninterrupted waveform of relatively low voltage spikes. Coagulation current has intermittent higher voltage spikes with intervening, ‘off periods’, lasting about 80% of the time. Blended current combines both waveforms.
• The principle of polypectomy is to coagulate the core (slow cook) of the polyp stalk, with its vessels, before transection.
• Polypectomy should be performed using coagulation current only at a low power setting (15-25 W). The maximum power setting used should be no more than 30-50W. We use ERBE settings of- coag 30W (forced) and set cut to zero and endocut is turned on. The ‘endo cut’ adjusts output automatically for appropriate heating during snaring.

Snares
The standard large snare is 2.5 cms in diameter and the small snare is 1 cms in diameter. The technique of application is the same irrespective of whether the snare is oval, crescent shaped or hexagonal.

Technique of polypectomy for pedunculated polyps

• Accessories like snare/forceps enter the viewing field at 5’o clock position. So polypectomy will be easier if the polyp is placed in the right lower quadrant of the field of view. A change of patient position may be needed for optimum position of the polyp.
• It is usually best to have the snare fully open, and then to manoeuvre only with the scope controls or shaft, so that the snare is placed over the polyp head almost entirely by manipulation of the scope. It may help to open the snare in the colon beyond the polyp, and then to pull the colonoscope slowly back until the polyp comes into the field of view and into the open loop.
• Ideally the snare should be closed at the mid-portion of the stalk. Initial snare closure should be gentle to ensure it is in the right place (once the wire has cut into polyp tissue it may be difficult to release and reposition it)
• Apply the current continuously for 5-10 seconds at a time, watching for visible whitening. The snare should be closed slowly and simultaneously.
• Piecemeal resection of the head may be performed if the polyp cannot be encircled with the snare, until the residual portion of polyp is small enough to permit encirclement with the snare (piecemeal resection of head is safe as the vessels in the head are much smaller than those in the stalk).

Hot biopsy principles

• Hot biopsy is an effective way of destroying polyps 1-5 mm in size. Polyps over 5mm in diameter are not suitable for hot biopsy removal. Using hot biopsy for larger polyps may cause the current to fan out from the point of contact of the forceps. This will heat tissue at a distance (invisibly) and predispose to the risk of perforation especially in the right colon.
• Principle- The hot biopsy forceps is an electrically insulated forceps through which electrical current flows to direct electrical energy around the tissue held within the jaws. The tissue within the jaw is protected from current flow, so is unheated (unless by thermal conduction resulting from long current application). Hot biopsy thus enables simultaneous cautery of the polyp base while obtaining a biopsy specimen.
• Current- settings are same as for snare polypectomy (usually 15 W coag)
• Technique of hot biopsy:
  • Only the apex of the small polyp is grasped in the jaws of the hot biopsy forceps.
  • Tent up the polyp onto a pseudo pedicle by withdrawing the forceps slightly (this prevents deep thermal injury to the colon wall)
  • Apply coagulation current for a maximum of 2-3 seconds.
  • Pull off the biopsy. Even if some of the head is uncoagulated, the basal blood vessels will have been destroyed and it will slough off.
  • Ensure that the black insulating plastic of the forceps is visible (so that the metal parts of the jaw is not in contact with the scope) before applying current.
• Safety-
  • Right colonic wall is very thin and so hot biopsy is best avoided in the right colon. Polyps 1-5 mm in size may be removed by cold snaring in the right colon. Cold snaring by cheese wiring is safe as small polyps have small nutrient vessels. Minor bleeding occurs, but this always stops in 1-5 minutes. Polyp lifting is not needed when using cold snare.

Sessile polyp

• Endoscopic mucosal resection (EMR) is usually used for removal of sessile polyps particularly in the right colon.
• Injection of fluid into the submucosa beneath the polyp increases the distance between the base of the polyp and the serosa. When current is then applied with a snare, the polyp can be more safely removed because of a large submucosal cushion of fluid. The fluid injected is normal saline or jelofusine with or without adrenaline (1 in 10,000). Some colonoscopists add a few drops of methylene blue to the fluid, the blue showing up the extent of the submucosal bleb. (One commonly used solution- jelofusine 40 ml, 2 ml of 1 in 10000 adrenaline and 0.5 ml of methylene blue). Upto 20-30 mls of the solution may be needed for large sessile polyps.
• Injection technique- Make the first injection proximal to the polyp, so that the raised bleb of tissue does not obscure the view. Subsequent injections are made into the edge of the preceding bleb or directly through the polyp surface (in thin polyps). The plane of separation in the submucosa for successful injection is very superficial. If a bleb is not being raised, withdraw the needle a bit. Failure to lift (non lifting sign) suggests malignancy, the lesion being fixed by invasion into deeper layers.
• Aspiration of air during attempted snare capture of elevated polyp will result in an easier encirclement.
• Complete removal should be attempted at the first endoscopic session because scarring will make subsequent attempts at EMR difficult.
• The basal remnants after most of the polyp has been snared can be safely destroyed by APC.
• The spot should be marked with monospot/India ink because further sessions will be needed to check the site.
• It is permissible to remove a much larger piece with EMR than one would ordinarily resect in the right colon. The pieces should probably be not larger than 2 cms in diameter

Rectal polyps

• Large sessile polyps up to 12 cm from the anal verge are extraperitoneal and may be better removed by local proctological techniques, which produce a single large specimen for optimum histology. A failed endoscopic attempt to remove such rectal polyps makes subsequent removal by the surgeon difficult.
• Sessile polyps more than 12 cms from the anal verge can be removed by transanal microsurgery or TEMS but is more often removed endoscopically

Polypectomy safety principles

• Marking the snare with a pencil or indelible pen at the point that the snare is just closed to the tip of the outer sheath is one of the most important safety factors in polypectomy. It allows the assistant to stop snare closure before the wire closes too far into the tube and there is danger of a smaller stalk being cut off by ‘cheese-wiring’ mechanically without adequate electrocoagulation; it also warns if the stalk is larger than apparent or head tissue or mucosa has become entrapped.
• Large stalks may be injected with adrenaline (1 in 10,000) before snaring to reduce the risk of bleeding. Nylon endoloops or metal clips may also be used for large stalked polyps, particularly in patients on anticoagulants or anti platelet agents. These may be placed before or after polypectomy. However, nylon endoloops are floppy and may be difficult to manoeuvre over a large polyp head. Clips can be applied to smaller stalks before or after polypectomy. However, it is important that the snare does not touch the clip as it may cause a burn to the colon wall.
• Tattooing marks the site of any suspicious or partially removed polyp for follow up or for surgery. 1 ml of India ink injected close to the polypectomy site is sufficient for endoscopic follow up, but four quadrantic injections ensure visibility if surgery is a possibility. The carbon particles of India ink remain in the submucosa for many years (probably for life).
• Only 1:200000 adrenaline is used in the rectum (compared with 1:10000 in colon) because there is a risk of communication to the systemic circulation and danger of cardiac dysrhythmias.

Polyp retrieval

Smaller polyps or fragments up to 6-7mm can aspirated in a polyp trap or more cheaply, onto gauze placed over the suction connector.
Larger specimens may be retrieved using the nylon Roth net or the multi prong grasping forceps or the basket. Roth net is capable of repeated openings and capture of several fragments. Thus, these devices may be able to retrieve up to 3-5 large polyps at a time

Trouble shooting

• Lost polyp after transection- Look for any fluid. The polyp is likely to be there as it is the dependent side of the colon. If no fluid is visible, squirt in some water with a syringe and watch where it flows. If the water refluxes back, the polyp is likely to be distal to the scope and the scope will need to be withdrawn to find the polyp.
• Snare loop is stuck in the wrong position- the snare loop can be released by lifting it up over the polyp head and pushing forcibly inward- with the whole colonoscope if necessary. The alternative is to sacrifice the snare by cutting it with wire cutters, withdrawing the scope and leaving the loop in situ. Either the polyp head will fall off or another attempt can be made with a new snare.
• Difficult sigmoid- Sometimes polypectomy may be difficult in sigmoid colon because of narrowing  either due to diverticular disease or hypertrophied folds. A gastroscope may allow easy snare positioning in the same location where the colonoscope was both cumbersome and difficult.

References

1. Wayne JD. Colonoscopic polypectomy. Diagnostic and therapeutic endoscopy 2000;6:111-124
2. Cotton PB, Williams C. Practical Gastrointestinal Endoscopy. The Fundamentals. 5th Ed

Bowel preparation for colonoscopy

Poor bowel preparation is a significant problem facing colonoscopist throughout the world. A prospective study by Bowels et al in 2004 showed that poor bowel prep accounted for 19.6% of failed procedures. In addition there is evidence that polyp detection rate is determined by the quality of bowel prep. It is inherent that poor preparation would make colonoscopy more hazardous. The existing regimens have been tabulated below.

Dietary modification

Dietary modification can be a useful adjunct to bowel preparation regimens. We recommend a 48 hr low residue and 24 hr liquid diet prior to the colonoscopy.

Safety
Absolute contraindications

• Gastrointestinal obstruction or perforation, ileus, or gastric retention
• Acute intestinal or gastric ulceration
• Severe acute inflammatory bowel disease or toxic megacolon
• Reduced levels of consciousness
• Hypersensitivity to any of the ingredients
• Difficulty swallowing due to nausea (a nasogastric tube may help)
• Ileostomy

Drug Modifications

Oral iron should be stopped 5 days before and appropriate advice is given for patients with diabetes. In addition patients on OCP need to be informed reduced bioavailability with bowel preparation agents and need for temporary alternative methods of contraception. Consider stopping ACE inhibitors, NSAIDs and diuretics as this may increase the risk of renal dysfunction and hypovolemia.

Failed Bowel preparation

In patients in whom preparation has failed clarify the factors that may have contributed.

• Unpalatability, lack of understanding/ failure to recognise the importance of following the regimen may be significant factors in compliance.
• Patients on opiods may need to temporarily use alternative agents.
• Diabetic / Constipated patients have slow gut transit and may need prolonged regimens.
• Adding a stimulant such as Senna or Bisacodyl may help.
• Combining preparations such as PEG and SPS agents may be successful.

References

ASGE Guidance

BSG Guidance

• Avoid any loops in the scope outside the patient or the umbilical cord. Presence of such loops prevent transmission of twisting (torquing) of the shaft to the tip.
• Avoid simply pushing in (without good views). This will cause loop formation in the colon between the tip and the anus
• Use torque steering to intubate the left colon. It minimises loop formation.  Torque steering is achieved by combining rotation of the scope shaft with up or down angulation of the scope tip. Use left/right wheel as little as possible in the left colon.
• Overangulation to get around the bends can be counterproductive. Overangulation of the scope tip leads to a walking- stick handle shape. This pushes the tip against the wall of the colon on the proximal side of the bend, obscuring views and leading to loop formation in the scope.
• Frequent withdrawal movements, combined with suction and torque steering helps avoid looping.
• Try different patient positions.  An acutely angled splenic flexure may be opened up and easier to negotiate with the patient on their right side or back. Similarly the hepatic flexure may be opened up and easier to negotiate with the patient on their left side, or on their back.
• Insufflate as little as possible

Resolving the loop
Loop formation can be recognised by loss of one-to-one progression of the shaft to tip or paradoxical movement of the tip. Loop is also recognised by patient discomfort and resistance to insertion.
Loop can be resolved by carrying out the following steps in sequence:

• Withdraw with clockwise torque and re-advance maintaining torque
• Withdraw with anti-clockwise torque and re-advance maintaining torque
• Change the patient position- supine to start with

PS- If there is no resistance to intubation and no patient discomfort, try and push through the loop.
Resolving recurrent loop
Apply the following steps in sequence

• Straighten loop
• Insert again
• If loop reforms, straighten loop and insert again using hand pressure over the sigmoid or transverse colon as appropriate; and
• When past the bend, withdraw to straighten, reapply abdominal pressure and insert again

INTUBATION
Step 1 Rectum
Pull back to distal rectum
Insufflate air above fluid level
Torque steer through the recto sigmoid junction
Step 2 Sigmoid colon
Loop inevitably occurs in the sigmoid colon.
3 types of loop can form in the sigmoid colon; alpha, reverse alpha and N loop
Alpha loop- It occurs when sigmoid is on a long mesentery and there are no adhesions allowing the sigmoid mesocolon to twist easily. An alpha loop is formed only in 10% of the colonoscopies. An alpha loop is a blessing as its shape means there is no acute bend between the sigmoid and descending colon, so the splenic flexure can be reached rapidly and relatively painlessly. Applying de looping manoeuvres half-way round an alpha loop is a potential mistake, since this may cause alpha loop to rotate back into an N-spiral loop, with much greater difficulty in reaching up the descending colon. It is thus wiser to pass straight on into the transverse colon at 90cms with the alpha loop in position. Alpha loop straightening is by strong clockwise derotation and withdrawal to 50-60 cms.
Reversed alpha loop- Mesenteric fixation variations occur in at least 15% of subjects. This may result in persistence of varying degrees of descending mesocolon. This unusually mobile descending colon forces the colon in an anticlockwise reversed alpha loop. This reversed alpha loop allows the scope tip to move into descending colon nearly as easily as alpha loop. Since around 90% of sigmoid loops spiral clockwise, this variation is significant to the endoscopists as it will need anticlockwise de rotation to resolve the loop.
N or spiral sigmoid loop- occurs if the sigmoid is on a short mesentery.  It is also formed when the sigmoid is on a long mesentery and the retroperitoneal fixation of the descending colon is low in the pelvis. Removal of N loop is essential to help passage into the descending colon. Straightening out N loop involves pulling back with clockwise (usually) twist. Most of the pain and difficulties experienced subsequently in colonoscopy (during intubation of splenic flexure, transverse and hepatic flexure) stems from recurrent or persistence N looping.
When one-to-one is lost at mid sigmoid colon (SC) usually due to N loop: try

• Clockwise pull back to see if this starts to advance scope tip
• If not try anticlockwise torque
• If unsuccessful- change position to supine and try again
• If unsuccessful- forceful push through is only occasionally required. It helps to warn the patient of a few moments of stretch discomfort. Then a firm but decisive pressure is applied to advance the scope tip into the descending colon. Then try and reduce loop again
• Abdominal hand pressure (inwards and downwards pressure towards the pelvis) often helps during sigmoid insertion, since the sigmoid frequently loops anteriorly close to the abdominal wall. Hand pressure in the left lower abdomen helps by reducing the size of the loop by acting as a buffer to transmit more of the inward push on the shaft toward the descending colon.

Step 3 Sigmoid descending junction (SDJ)
The SDJ is the trickiest point of examination for most colonoscopists. SDJ conventionally appears as an acute bend at around 40-70 cms. Follow the steps a-e above to reach descending colon. Once in the descending colon- push in maintaining torque to reach the splenic flexure.
Step 4 Splenic flexure (if acute or underwater, change position)

• Check the length of the scope: if greater than 50-60 cms: pull back to straighten the scope to 50 cms
• Insert scope with clockwise twist to control sigmoid looping (remember paradoxical movement may occur initially if splenic flexure has been pulled down by colonoscopic withdrawal). If looping occurs, try stiffening scope stiffener.
• If not progressing, change position to supine or right lateral.
• If not working- use sigmoid hand pressure

Reversed splenic flexure- Scope tip passes laterally rather than medially around the splenic flexure, because the descending colon has moved centrally on a mesocolon (normally desc colon is fixed retroperitoneally). Here clockwise torque doesn’t work and an anticlockwise torque will be needed to push to hepatic flexure
Step 5 Transverse colon

• Distal transverse colon- keep clockwise torque and use scope stiffener if needed.
• Mid transverse colon-hepatic flexure

Scope forms a transverse loop- this often forms a sharp bend
Steer around the angulation into proximal TC. Remember scope advances with steering (avoid impaction on opposite wall)
The most important manoeuvre is to pull back repeatedly (repeated in and out movement- like playing a trombone) – this lifts up the transverse loop and advance to hepatic flexure.
Anti-clockwise torque helps advance the scope in proximal transverse colon. If necessary change position or apply hand pressure (see below)
If unable to reach hepatic flexure by pulling back: push through transverse loop to advance scope tip and repeat.
The hepatic flexure may be pushed down by asking patient to hold a deep breadth
Sometimes a gamma loop may form in a very long redundant TC. It is large and rarely removable. Push through the loop to reach caecum.
(Hand pressure over TC- Hand pressure over TC is helpful in about 30% of transverse colons. Hand pressure may be applied over left hypochondrium- to push the whole loop toward HF, mid-abdomen- to counteract the sagging TC or right hypochondrium- to impact directly on the HF. It is worth remembering that sigmoid tend to re loop at all stages of the examination. Thus sigmoid pressure is also a good bet whenever the scope is looping)

Step 6 – HF to caecum (the ascending colon and caecum are fixed retroperitoneally)
On seeing the AC, the temptation is to push in. However this may re-form the transverse loop. The trick is to aspirate air and pull back the scope. When the tip starts to fall back- reinsert
Intubation of caecal pole may be easier in supine position
Identifying caecum

• At the caecal pole the three taeniae fuse around the appendix to form a crow’s foot or ‘Mercedes Benz’ sign
• Crescentic appendicular slit. The operated appendix looks no different unless it has been invaginated into a stump, when it can sometimes resemble a polyp. (Beware- take a biopsy and do not attempt polypectomy)
• Ileocaecal valve- situated about 5 cms from the caecal pole

Step 7- Terminal ileum
TI intubation may be easier in left lateral position
Aspirate air to make the ICV obvious
Observe ICV from 5-10cms above valve. Predict opening to TI by observation and appendix orifice (bow and arrow trick- see below)
Rotate scope and bring ICV at 6’o clock position
Insert scope over IC valve
Pull back scope onto first major fold
Insufflate with very slow pull back until TI mucosa seen.
Enter TI
The TI can also be entered by direct intubation if opening is visible
Bow and arrow trick to enter TI
Find the appendix orifice
Imagine an arrow pointing in the direction of the appendix lumen
Angulate in that direction and pull back (still angled) for about 3-4 cm
At this point expect the proximal lip of the ICV to start to ride over the lens
Insufflate with very slow pull back- twist or angle gently to enter TI.
Step 8 Retroversion in rectum
Rectum is very capacious and hence retroversion is important to examine rectum completely. The most distal part of rectum is especially a potential blind spot.
Choose the widest part of rectum and angulated both controls fully and push inward to invert the tip toward the anal verge.
Retroversion is not always possible in a small or narrowed rectum

Ref- Cotton PB, Williams C. Practical Gastrointestinal Endoscopy. The Fundamentals. 5th Ed