Major parts of an endoscope fundus

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Gastrointestinal Endoscopy Basics Pg. 1
Jeffrey K. Saur, DVM, DA BVP

In-Hos pital Basic Training Opportunities
Flexi ble Gastrointestinal Endoscopy
Canine and Feline

Syllabus

Major parts of an endoscope
Insertion tube
Tube
Bending section
Distal t ip
Image guide objective lens
Insufflation channel
Accessory channel
Irrigation channel
Light guide objective lenses
Handpiece
Suction valve
Air/water valve
Accessory channel opening
Up/down deflection knob
Up/down deflection lock
Left/right deflection knob
Left/right deflection lock
Eyepiece with ocular lens
Diopter adjustment ring
Umbilical cord
Light guide connector
Connector to suction pump
Connector to air pu mp for insufflat ion
Connector to water bottle for irrigation
Pressure compensation valve: Remove cap and pl acard for use and routine cleaning
Care of the endoscope
Always handle the insertion tube carefully; avoid sharp bends, tight coiling, or accidental striking of
the tube against hard surfaces
The fingers should never manipulate the distal deflecting portion of the endoscope; the control knobs
should be used to check the range of motion of the deflecting tip.
Excessive force on the control knobs should always be avoided (make sure deflecting locks are off).
Always use an oral speculum when passing the endoscope through the oral cavity of an anesthetized
patient
Never force instruments or pass foreign objects through the accessory channel.
Pressure compensation valve: Remove red cap and placard fro m scope
Red cap should be on scope ONLY
For ethylene o xide sterilization
Transportation/shipping (altitude changes of >2500 ft)
Holding the endoscope
Hold in left hand
Left index finger controls suction valve
Left index or middle finger can control air/water valve
Left thumb controls up/down deflection knob
Right hand
Controls left/right deflection knob
Inserts channel accessories
Advances insertion tube
Applies rotational torque to insertional tube
Gastrointestinal Endoscopy Basics Pg. 2
Jeffrey K. Saur, DVM, DA BVP

Accessory channel and instruments
“Disposable” instruments that are not compatible with endoscope may damage the accessory channel
Instrument diameter should not exceed that recommended b y the manufacturer
Instruments should never be forced through the channel when resistance is felt
Foreign objects should not be removed through the instrument channel: Instead, the entire endoscope
should be removed fro m the patient once the object has been firmly grasped
Before passing instruments through the deflected tip, the manufacturer’s reco mmendations should be
reviewed.
Irrigation: Fill the irrigation bottle 2/ 3 fu ll with de-ionized or distilled water
The use of de-ionized or distilled water will reduce the incidence of mineral deposits clogging the
irrigation channel
Cleaning, disinfection and sterilization
A pressure check is done immediately after use to ensure that no leaks have developed.
If a leak has occurred, DO NOT CLEAN THE ENDOSCOPE.
Call Karl Stro z immed iately.
Avoid applying cleaning solutions to ocular lens and to diopter adjustment ring
Next, organic material should be mechanically removed fro m all surfaces of the endoscope and other
surfaces.
All external surfaces should be wiped down with gauzes soaked in cleaning solution
Remove suction valve and replace with cap.
Cleaning solution is suctioned through the accessory channel to remove debris and soften any
adherent debris.
Cleaning brushes should then be passed through all channels s everal times to remove adherent
debris before it has the opportunity to dry.
Passing the cleaning brush through the channel rapid ly may cause damage
A back-and-forth scrubbing motion within the channel may cause damage
The balance of the cleaning solution is then suctioned through the accessory channel
A final rinse of de-ionized or distilled water is suctioned through the channel.
All external surfaces are rinsed or wiped with de-ionized or distilled water.
A final wiping down is done with 70% isopropyl alcohol-soaked gauze.
Drying the endoscope
Empty the irrigation bottle, and reattach
Place cleaning cap on air/ water valve
Turn on air pu mp. This will expel the residual water fro m the irrigation channel.
Then turn-on suction pump to air-dry the accessory channel
Wipe down all external surfaces with clean, dry gauze.
The air pu mp and suction should be left on 10 minutes before hanging scope for storage (longer if
endoscope is stored in the case).
Instruments
The instruments should be rinsed well with warm water to remove debris.
Place them next in an u ltrasonic cleaner with cleaning solution
Rinse the instruments with water
Apply instrument milk, hang, and allow dry ing.
Cold sterilization or ethylene o xide sterilization may be used.
Autoclaving may be used if all parts are autoclave-safe
A commercially available en zy matic cleaning solution designed for endoscopes and accessories is
highly reco mmended
Detergezy me (item # MX4500)
Available through
Med-Vet International
(847) 680-3050
Does Karl Storz recommend the use of other solutions, such as dilute betadine, Nolvasan®, dish
soap, or Cidex?
All lens surfaces and light guide surfaces should be wiped with 70% alcohol to remove residual
cleanser film that may co mpro mise light and image transmission
Gastrointestinal Endoscopy Basics Pg. 3
Jeffrey K. Saur, DVM, DA BVP

First of all, do no harm
If too much air is insufflated, especially in s mall dogs and cats, the stomach may become quite
distended, causing significant comp ro mise of respiratory capacity.
In extreme cases, venous return fro m the abdomen may also be compro mised.
When an examination is finished, suction as much air as possible fro m the stomach.
During withdrawal, any fluid observed in the esophagus should be suctioned.
Gastrointestinal Endoscopy Basics Pg. 4
Jeffrey K. Saur, DVM, DA BVP

Esophagogastroduodenoscopy (also referred to as gastroduodenoscopy, or endoscopy)
When possible, patients should be fasted for at least 12 hours prior to the procedure.
At least 24 hours should pass from the comp letion of any bariu m series.
Residual bariu m should NOT be suctioned through the accessory channel. Bariu m is very
adherent, and is difficu lt to re move.
Known esophageal or gastrointestinal perforation is a contra-indication fo r
esophagogastroduodenoscopy.
Positioning of the patient and the scope
The classic position for the patient undergoing endoscopy is left lateral recu mbency.
An oral speculum should ALWAYS be used for esophagogastroduodenoscopy
The endotracheal tube should be tied in firmly either behind the patient’s head, or to the lower jaw (do
not entrap the tongue in the tie)
A long, flat surface in front of the patient is best. This allo ws the endoscope to be kept straight, which
allo ws for better control, orientation, advancement and application of torque to the endoscope.
Esophagoscopy
Esophagoscopy is the method of choice for diagnosing disorders of the mucosa or causes of
obstruction of the lumen, including esophagitis, stricture, foreign bodies, and neoplasia.
Other disorders for wh ich esophagoscopy is valuable are esophageal diverticulu m, vascular ring
anomaly, gastroesophageal intussusception, megaesophagus, hiatal hernias, and
periesophageal compression.
Terminology
Dysphagia: Difficulty in swallowing
Odynophagia: Pain on swallowing
Ptyalis m: Excessive salivation
The scope is passed dorsally over the laryn x, avoiding the piriform recesses laterally.
Conditions:
Megaesophagus
Congenital megaesophagus: Occurs in several can ine breeds, as well as Siamese cats
Adult-onset megaesophagus
Idiopathic
Secondary to myasthenia gravis, poly myositis, peripheral neuropathies, CNS disease,
dysautonomia, lead to xicity, hypothyroidism, or hypoadrenoco rticism.
General anesthesia makes the esophagus flaccid and dilated
Esophagoscopy may be normal in animals with mild hypomotility
A dilated esophagus without any insufflation is suspect. The presence of pooled fluid, froth,
and/or food is more consistent with a diagnosis of megaesophagus.
Esophageal diverticula: Large, circu mscribed saculations of the esophageal wall, o ften containing
flu id and/or ingesta.
Vascular ring anomalies
A persistent right aortic arch accounts for 95% of vascular ring malformation s
A stricture is present at the base of the heart, with d ilat ion of the esophagus proximal, and
normal esophageal diameters distal to the stricture.
Pulsations are present at the level of the stricture
Esophagitis
The common causes of esophagitis include in jury fro m gastroesophageal reflu x during
general anesthesia, esophageal foreign bodies, hiatal hernia, gastric emptying disorders,
persistent vomiting, indwelling nasogastric tubes, ingestion of caustic irritants, and
thermal injury fro m ingestion of overheated food (microwaved).
Esophagitis caused by gastroesophageal reflu x is related to the duration of mucosal contact
with reflu xed gastric acid, pepsin, bile salts and trypsin.
Clin ical signs from esophagitis secondary to anesthesia are usually seen 2-4 days post
anesthesia.
Lesions observed on esophagoscopy include mucosal erythema, hemo rrhage, friab ility,
irregularity, erosions, ulcers, pseudomembranes, indistensibility, and stricture.
Esophageal stricture
Gastrointestinal Endoscopy Basics Pg. 5
Jeffrey K. Saur, DVM, DA BVP

Visualized as a circu mferential smooth ridge or ring of fibrous tissue
Balloon dilation is the treat ment of choice.
Referral to a facility that is prepared to handle an esophageal perforation is reco mmended
even though balloon dilat ion itself is a straightforward p rocedure.
Esophageal perforation
May occur during endoscopic removal of a fo reign body, or stricture dilation.
Clin ical signs from esophageal stricture secondary to anesthesia are usually seen around 10
days post anesthesia.
Clin ical signs include anorexia, depression, odynophagia, fever, pain , cough, and/or dyspnea.
Thoracic radiographs may demonstrate med iastinitis, pneumo mediastinu m, pneu mothorax,
soft-tissue emphysema, and pleural effusions.
Endoscopy should NOT be performed in cases of known esophageal perforation
Esophageal fistulas are congenital or acquired co mmunicat ions between the esophagus and the
tracheobronchial tree, mediastinu m, or pleural space.
Hiatal hernias and gastroesophageal intussusception
A sliding hiatal hernia is a protrusion of the abdominal segment of the esophagus a nd cardia
region of the stomach through the esophageal hiatus into the thorax.
A paraesophageal hiatal hernia occurs when a portion of the stomach (fundus) herniates
through the hiatus into the caudal mediastinum along the caudal thoracic esophagus.
A gastroesophageal intussusception is an invagination of the stomach into the lumen of the
caudal esophagus.
To reduce the intussusception, apply digital pressure to the cervical esophagus and
maximally insufflate. The endoscope may be used to gently push the
intussusception caudally.
Monitor for respiratory co mpro mise.
Esophageal neoplasia
Primary esophageal neoplasia is rare.
Multiple b iopsies from the same location should be obtained, especially if the surface is
inflamed or necrotic.
Firm masses may be biopsied by first stabbing repeatedly with a retractable
injection/aspiration needle, then grasping with the biopsy forceps.
Esophageal foreign bodies
See foreign body section
Gastroscopy
Gastroscopy is a valuable tool for diagnosing primary gastric d isorders including chronic gastritis,
superficial gastric erosions, gastric foreign bodies, gastric motility disorders, ulcers, and
neoplasia.
Gastroscopy should be considered anytime there is hematemesis
Preparation
See notes at start of esophagogastroduodenoscopy
Atropine and other anticholinergic d rugs are not used unless they are required to maintain heart
rate.
Opioid d rugs should not be used as they may increase pyloric tone.
Anatomical terms
Card ia
Fundus
Body
Angularis (incisura angularis)
Antrum
Pylorus
Greater curvature
Lesser curvature
During the in itial examination, note any fluid or ingesta present, the ease with which the gastric walls
distend with insufflation, and the gross appearance of the rugal folds and mucosa.
Green or yello wish fluid may indicate reflu x of intestinal contents into the stomach.
Gastrointestinal Endoscopy Basics Pg. 6
Jeffrey K. Saur, DVM, DA BVP

To remove fluid, position the endoscope tip parallel to the flu id and gastric wall, and suction
flu id.
Avoid suctioning fluid with part iculate matter. Debris can lodge in the accessory
channel, clogging, and potentially damag ing the channel.
A retroflex v iew should be attempted/obtained to fully evaluate the cardia for lesions.
To access the antrum, counterclockwise rotation on the up/down knob is used as the scope is
advanced along the greater curvature.
To access the pylorus, the pyloric opening is kept centered in the field of vision as the scope is
advanced.
Gentle, continuous pressure is applied to advance the scope through the pylorus.
Once passed, clockwise rotation of both directional knobs may help advance the scope into
the proximal duodenum.
If this fails, a biopsy forcep may be passed through the pylorus, and then the scope advanced
over the forcep into the duodenum.
Monitor the patient as stretching and displacement of the gastric body and pylorus may elicit
vagal stimu lation resulting in a bradycardia.
Biopsy techniques
The stomach should be only moderately insufflated, allowing for grasping of pro minent rugal
folds.
The biopsy forceps are advanced towards the mucosa at an angle of 45 o to perpendicular to the
mucosa.
The biopsy forceps are advanced to a fold, opened, advanced, and closed.
The forcep is withdrawn steadily, with the biopsy sample shearing -off as it enters the accessory
channel. Only in cases of significant disease will the fo rceps “bite off” tissue.
Biopsies of ulcers and erosions should be obtained from the margins. Th is reduces the amount of
inflammatory or necrotic tissue obtained, reduces the possibility of a perforation, and
maximizes the diagnostic tissue.
Masses should be biopsied repeatedly and deeply. Chose a site that can be approached easily.
Then, biopsy the same site repeated, digging into the mass.
Conditions and diagnoses: In general, let the pathologist make the diagnosis.
Gastritis: Mucosal erythema, mucosal irregularity, friability, hemorrhage, erosions,
Helicobacter-associated gastritis: Pathologists will find this. Don’t sacrifice a biopsy for culture
or for a urea slat test.
Erosions and hemorrhages
Erosions: A shallow defect in the mucosa that does not extend into the submucosa.
Hemorrhage: Discrete petecchiae or bright-red streaks not associated with visible breaks in
the mucosa.
Associated with: stress lesions, critical illness, localized gastric trau ma, ingestion of
corrosives, radiation, drugs (especially NSAIDs), discrete ischemia, mast cell tumo rs,
and idiopathic chronic erosions.
Ulcers: An erosion that has breached the muscularis mucosa.
Gastric polyps
Gastric neoplasia:
Adenocarcinoma is the most common gastric tumor in the dog.
Ly mphosarcoma is the most common gastric tu mor in the cat.
Duodenoscopy
Regions:
Pro ximal duodenum
Pro ximal flexure
Descending duodenum
Major duodenal papilla
Minor duodenal papilla (in dogs)
Caudal or colic flexu re
Ascending duodenum
Descriptors
Gastrointestinal Endoscopy Basics Pg. 7
Jeffrey K. Saur, DVM, DA BVP

Cobblestone
Erosion
Erythema
Fibrinous
Fissures
Grainy
Granular
Irregularity
Proliferative
Roughened
Shaggy
Swollen villi
Velvety
White discoloration
Biopsy procedures
Do not biopsy the major or minor duodenal papillae
The biopsy forcep is opened, advanced to a specific target, closed, and retracted.
The biopsy forcep is passed (blindly) until resistance is felt, retracted slightly, opened, advanced,
closed, and retracted.
The biopsy forcep is opened, advanced (blindly) against the mucosa until resistance is felt, closed,
and retracted. Strips are often obtained in this manner. Depending on technique, a strip may
break off, but can be retrieved by advancing the scope until it is visualized, then grasped
with the biopsy forcep, and retracted.
Conditions
Inflammatory bowel disease
Ly mphangiectasia
Swollen villi
White discoloration
Give 1-2 tablespoons of corn oil the night before the procedure to increase microscopic and
macroscopic lesions.
Intestinal parasites
Neoplasia: Ly mphosarcoma, adenocarcinoma, mast cell tu mors, leio myo ma, leio myosarcoma,
fibrosarcoma, ganglioneuro ma, and carcinoid tu mors.
Protein losing enteropathies: A special consideration needs to be taken with those patients having
low total p rotein and/or low albu min. So me of these patients will have inapparent pleural
effusion that can compromise anesthesia. Thoracic radiographs should be taken prior to
anesthesia to assess for the presence of a pleural effusion.
Gastroduodenoscopy
This is the primary upper gastrointestinal endoscopy procedure. When generalized disease is
suspected, the endoscope is rapidly advanced as far distally into the duodenum as possible.
Inspection and biopsies are performed during withdrawal. By min imizing gastric man ipulation
and insufflation, the pylorus is more easily entered, thus reducing procedure time.
Ileoscopy, colonoscopy and colonoileoscopy
Colonoscopy
Used to diagnose inflammatory d isorders, neoplasia, and fungal in fections.
Preparation
The patient is withheld fro m food for 36 hours.
The patient receives a combination of o ral lavage and cathartic solutions, and enemas (see
attached colonoscopy preparation form).
The patient is positioned in left lateral recu mbency
A digital rectal exam is performed to detect any distal lesions.
The endoscope is then introduced into the rectum, using the digit to guide the scope tip past any
folds in the rectum.
The endoscope is advanced to the ileocolic junction.
Gastrointestinal Endoscopy Basics Pg. 8
Jeffrey K. Saur, DVM, DA BVP

The feline cecu m is a blind pouch. If advancing the endoscopy is not improving visualizat ion,
retract the scope and insufflate. The scope may already be in the cecum. A b iopsy
forcep may be advanced to push the mucosa away fro m the endoscope to allow fo r
better visualizat ion and recognition of the ileocolic valve.
Ileoscopy
Preparation is necessarily the same as it is for co lonoscopy.
Unless the approach angle to the ileocolic valve is straight, advancing the endoscope into the
ileu m can be difficu lt.
Placing the patient in dorsal recu mbency may help. Once the endoscope has been successfully
passed into the ileu m, the patient is returned to left lateral recu mbency.
The biopsy forcep may be passed through the valve, and then the endoscope advanced over it.
Biopsies with colonoileoscopy
Biopsies are obtained during withdrawal of the endoscope.
Only moderate insufflation should be used.
About 4-6 biopsies of the ileu m should be obtained when possible.
At least two biopsies should be obtained from each reg ion: cecu m, ascending colon, transverse
colon, high descending colon, and lower descending colon.
Multiple b iopsies of specific lesions should be obtained and submitted in a separate container.
When indicated, consider submitting a biopsy sample fo r Salmonella culturing, which can be an
intracellular organism missed during fecal cultures.
Post colonoileoscopy
Suction excess air
Theoretically antib iotics are not needed.
Analgesics also are not needed.
Conditions
Colitis
Strictures and obstructions
Extramural obstruction: Smooth, normal appearing mucosa at level of obstruction
Intramural obstruction: Similar to ext ramural, but often with some mucosal changes
Mucosal disease is evident by irregular, roughened, highly inflamed mucosa.
Neoplasia
Approach based on clinical signs
When vomiting is the chief presenting complaint, b iopsies obtained by gastroduodenoscopy is
indicated.
Cats, though, may p resent with vomiting due to lesions anywhere in the small intestine,
ileocecocolilc area, or pro ximal co lon.
Diarrhea may or may not be present.
When chronic small bowel diarrhea and/or weight loss occurs, especially with panhypoproteinemia,
biopsies should be obtained by gastroduodenoscopy and ileoscopy.
When chronic, nonspecific diarrhea is present, biopsies should be obtained by gastroduodenoscopy and
ileocolonoscopy.
When hematochezia, chronic vomiting (especially cats), dyschezia, tenesmus, and constipatio n are
present, colonoscopy is indicated.
Foreign bodies
Esophageal foreign bodies
Most esophageal foreign bodies lodge at the thoracic inlet, the base of the heart, or at the lower
esophageal sphincter.
Clin ical signs associated with an esophageal foreign body include salivation (which may include
blood), regurgitation, odynophagia, dysphagia, retching, and anorexia.
Gastric foreign bodies
The most common clinical sign associated with a gastric foreign body is vomit ing, wh ich may be
intermittent. Inappetence, anorexia, malaise, and abdominal tenderness may also be seen.
General approach
Obtain thorough radiographs. These may include cervical, thoracic and abdominal radiographs to
evaluate for mult iple foreign bodies.
Gastrointestinal Endoscopy Basics Pg. 9
Jeffrey K. Saur, DVM, DA BVP

Thoracic radiographs should be evaluated for evidence of an esophageal perforation.
Pneumo mediastinu m, pneu mothorax, subcutaneous emphysema, and/or pleural
effusions may be seen.
Abdominal radiographs should also be evaluated for signs of a perforation. Ev idence of free
air o r a peritoneal effusion may indicate a perfo ration, and surgery should be
considered.
Wood and most plastic foreign bodies are radio lucent, and will not be evident on radiographs.
An air gastrogram may make these more ev ident, whereas a bariu m series may mask the
foreign body, and subsequently interfere with an endoscopic inspection.
When the history indicates, gastric and duodenal biopsies should also be obtained after a foreign body
is removed. A prime examp le is when chronic vomiting was present prior to a known time o f
foreign body ingestion.
Esophageal foreign bodies should be removed as soon as possible.
Gastric foreign bodies should be removed if they are causing clinical signs, are unlikely to pass, are
long and/or sharp, or are co mposed of toxic materials.
Gastric foreign bodies that are best removed surgically include corncobs, rocks over 1-2 cm in
diameter, balls, heavy objects, large pieces of cloth.
Co mplications of endoscopic foreign body retrieval include perforation, lacerations, worsened
impaction, pyothorax, pneumothorax, pneumo mediastinum, and peritonit is.
Equip ment
Very basic
Alligator grasping forcep
Snare
Wire basket
Overtube
Bolt grabber
Additional retrieval equip ment: Two- or three-prong grasper
Esophageal foreign bodies
The patient is placed in left lateral recu mbency. This positions the esophagus above the aorta.
A foreign body should be retrieved, or pushed into the stomach. So me foreign bodies may only be
pushed to the distal esophagus, but this then allows for a surgical approach through a
gastrotomy to grasp and retrieve the foreign body through the lower esophageal sphincter.
All of these methods are preferable to esophageal surgery.
When lodged kibble is unexpectedly encountered, copious lavaging and patience may reduce the
kibble to mush, and minimize any mucosal damage.
A foreign body may be part ially embedded in the mucosa. An overtube may help d ilate the
esophagus and aid in the removal of the foreign body.
Fishhooks: Overtubes are very helpful.
The fishhook may be drawn inside the overtube, or the prongs pulled tight against the
overtube, which then allows for safe withdrawal of the fishhook.
The overtube may be aligned snuggly against a lodged fishhook, and then forcefully thrust
caudally to dislodge it.
A deeply embedded fishhook may be retrieved through a combination of thoracotomy and
endoscopy. The penetrating barb may be snipped off surgically, and the balance of the
fishhook retrieved endoscopically. This eliminates the need of a full -thickness
esophageal incision.
Bolt grabbers (obtainable at auto parts and hardware stores) may be passed next to the endoscope
to grasp large objects
Make sure to file down any sharp edges on the grabbers to prevent injury to the patient and
tears to the endoscope.
The bolt grabber may also be advanced through a separate overtube.
When perforation is possible, follow-up thoracic radiographs should be taken at 12 and 24 hours
post-procedure to evaluate for pneumo mediastinu m, pneu mothorax, and/or subcutaneous
emphysema.
Gastric foreign bodies
Gastrointestinal Endoscopy Basics Pg. 10
Jeffrey K. Saur, DVM, DA BVP

No matter how long the foreign body has been present in the stomach, rad iographs should be
obtained immediately prior to anesthesia to insure that the foreign body hasn’t finally passed
out of the stomach.
Linear foreign bodies that extend through the pylorus may b e gently tugged on. If resistance is
felt, the patient should be taken to surgery.
Pennies minted since 1982 contain a to xic level of zinc, which is rapid ly freed by the action of
stomach acid. Immed iate removal by induced vomit ing, endoscopy or surgery is essential.
A penny, nickel and dime should be placed next to the patient and a radiograph taken. This
can aid in determining which coin(s) might be in the stomach. A folded towel may be
placed under the coins to approximate the thickness of the body wall and fat. This may
help in maintaining the same degree of magnificat ion that occurs based on the distance
between the subject and the film p late.
A lot of nuts and bolts are zinc-coated, and should also be removed immediately.
Bolt grabbers (obtainable at auto parts and hardware stores) may be passed next to the endoscope
to grasp large objects
Make sure to file down any sharp edges on the grabbers to prevent injury to the patient and
tears to the endoscope.
The bolt grabber may also be advanced through a separate overtube.
Once a foreign body has been retrieved, the entire stomach and duodenum should be inspected for
any remaining fo reign material for the procedure to be considered completed.
Duodenal foreign bodies
Linear foreign bodies may be gently tugged on. If resistance is felt, immed iately proceed to
surgery.
A lot of duodenal foreign bodies have the aggravating habit of advancing distally at the approach
of the endoscope. This is partially due to the air insufflation. This expands the lumen, wh ich
then frees the foreign body and allows the air to push it or peristalsis to carry it d istally, until
it is out of reach.
Those duodenal foreign bodies that stay put are often so firmly lodged that surgery must be used
to retrieve them.
Gastrointestinal Endoscopy Basics Pg. 11
Jeffrey K. Saur, DVM, DA BVP

COLONOSCOPY PREPARATION
(Or, Th ings Are Looking Up)

The following is a reco mmended procedure and timetable for preparing a patient for colonoscopy.

Oral lavage
Two days prior to procedure
Confine
Start fast (water OK) in evening after highly-d igestible meal (I/ D, A/D)
Open magnesium citrate, pour in pan, and allo w de-fizzing overnight
One day prior to procedure
Have owner drop-off pet first thing in the morning
Water OK at all t imes during preparation, but DO NOT FEED
HOSPITALIZE UNTIL AFTER PROCEDURE IS DONE
The lavage solution should produce a copious, unpredictable diarrhea that can ruin a
client’s house, carpets, and a good client-Veterinarian relationship
Give Reglan 0.1 mg/ LB IM at ad mission
15 minutes later, ad min ister
Magnesium citrate 10 - 15 cc/ LB PO
Dogs: May need to stomach tube
Cats: Nasogastric tubes work well
Place cat in cat bag, apply cat muzzle
Place 2-3 drops ophthalmic topical anesthetic down left nostril
Apply light layer o f lubricant to 3 1/2 or 5 fr red-rubber feeding tube
Lidocaine jelly works best
K-Y Jelly OK
Slowly advance feeding tube through nostril while firmly holding the cat’s
head with other hand (1-2 technicians holding cat down in bag)
When full length of feeding tube is in, slowly flush tube with 3 - 6 cc NaCl
to make sure you’re in the esophagus, not the trachea.
Slowly ad minister fluid through nasal tube
Pinch off tube, then gently and slowly remove tube
Un mask and unbag the (probably upset) cat
Take dogs for frequent walks throughout day
Make sure cats have ample litter bo x and litter
In late afternoon, repeat Reglan IM
15 minutes later, Use Go-Lytely at 10 – 15 cc/ LB PO
Day of procedure
Dogs
Give gentle, warm water enema of 10 - 15 cc / LB first thing in the morning
Repeat in 2 hours
Cats:
Give gentle, warm water enema of 9 cc / LB first thing in the morning
Repeat in 2 hours
If patient appears to have “cleaned itself out”, place in clean cage and wait for time of p rocedure
Colonoscopies generally are done between noon and closing
Anesthetic protocol as indicated by the patient’s overall health status
NO NITROUS
Narcotics should be avoided as they may cause intestinal spasms and make it more d ifficu lt to
enter the ileu m
Gastrointestinal Endoscopy Basics Pg. 12
Jeffrey K. Saur, DVM, DA BVP

COLONOSCOPY PREPARATION

Enemas
I recommend doing two enemas the morning of the procedure after having done the usual oral lavage
preparation the day before, especially if little or no diarrhea has been produced, or if feces are still evident
on rectal:
Enema: Warm water only
Lactulose may also be used : 1 part per two parts water
Pass large French feeding tube to level of last rib
Admin ister prescribed amount of enema mixture rectally
Return to cage, or take dogs for walks
I find it helpful to hold the cat’s tail firmly over the rectum and between its rear legs
until the cat is placed safely back in its cage (small dogs as well)
In general, I have found using only an enema as preparation inadequate in that there is usually fresh ingesta
entering the upper colon during the colonoscopy.

Hi nts on using the Go-Lytel y lavage solution

This is availab le by prescription in a powdered form in a 4 liter container. Obviously our little patients are
not going to require the whole jug. I reco mmend making up an appropriate amount in a separate jar (like
500cc for a cat) and preserving the balance for future procedures.

If you have a gram scale,
Weigh the powdered contents
Record total weight of powder, and the amount to make 500cc when co mbined with water, which
will be 1/8th of the total weight of the powder
Record amount in grams to make 500cc on jug
Return balance to jug and store
Mix appropriate number of 500cc aliquots for the job in a separate container

If you don’t have a gram scale
Pour powder into clean, very dry 60cc syringe or appropriately sized measuring cup
Record total volu me of powder, and the amount to make 500cc when comb ined with water, wh ich
will be 1/8th of the total volu me of the powder
Record amount to make 500cc in units of measure on jug (cc, Tbsp, cups, etc.)
Return balance to jug and store
Mix appropriate number of 500cc aliquots for the job in a separate container
Gastrointestinal Endoscopy Basics Pg. 13
Jeffrey K. Saur, DVM, DA BVP

References

Chamness JJ: Endoscopic instrumentation. In Tams TR, editor: Small Animal Endoscopy (2nd ed.): Mosby,
Inc., St. Louis. pp 1-16. 1999.

Leib MS: Esophageal strictures. Proceedings of the 18th Annual ACVIM Foru m. pp 557-559. 2000.

Moore LE: The pros and cons of endoscopy. Proceedings of the 20th Annual ACVIM Foru m. pp 533 -534.
2002

Sherding RG, Johnson SE & Tams TR: Esophagoscopy. In Tams TR, editor: Small Animal Endoscopy (2nd
ed.): Mosby, Inc., St. Louis. pp 39-96. 1999.

Tams TR: Endoscopic examination of the s mall intestine. In Tams TR, ed itor: S mall Animal Endoscopy
(2nd ed.): Mosby, Inc., St. Louis. pp 173-215. 1999.

Tams TR: Endoscopic removal of gastrointestinal foreign bodies. In Tams TR, ed itor: Small Animal
Endoscopy (2nd ed.): Mosby, Inc., St. Louis. pp 247-295. 1999.

Tams TR: Gastrointestinal endoscopy: Instrumentation, handling technique, and maintenance. In Tams TR,
editor: Small Animal Endoscopy (2nd ed.): Mosby, Inc., St. Louis. pp 25-38. 1999.

Tams TR: Gastroscopy. In Tams TR, editor: Small Animal Endoscopy (2nd ed.): Mosby, Inc., St. Louis. pp
97-172. 1999.

Willard M D: Colonoscopy. In Tams TR, editor: Small Animal Endoscopy (2nd ed.): Mosby, Inc., St. Louis.
pp 217-245. 1999.

Willard M D: Rare esophageal diseases that are not rare if you look fo r them: Proceedings of the 18th
Annual ACVIM Foru m. pp 33-35. 2000.

Zoran D: Protein-losing enteropathies. Proceedings of the 75th Annual Western Veterinary Conference.
Vet-122. 2003.