Whole-Bowel Irrigation 

The rationale behind whole-bowel irrigation (WBI) is to prevent absorption of ingested matters (eg, extended-release medications, drug packets) by inducing a liquid stool through use of a osmotically balanced polyethylene glycol electrolyte solution (PEG-ES).^{[1, 2]}

Administration of PEG-ES (commonly known as Go-LYTELY) generally requires use of a nasogastric (NG) tube because of the large volume (over 1 L in an average adult) that must be ingested over a short period. However, if insertion of an NG tube is difficult, an awake and alert patient may drink the solution instead.

In 2004, the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists updated a position statement on WBI and other gastrointestinal (GI) decontamination methods.^[2] This position statement, based on literature reviews and expert agreement, serves as a guideline for the management of in-hospital poisoned patients. Because of the lack of controlled clinical trials showing that WBI improves clinical outcome, WBI is not recommended as a routine GI decontamination method for the poisoned patient. It should, however, be considered in certain situations (see Indications and Contraindications below for details).^[3]

Whole bowel irrigation may be considered in the following circumstances:

1. Prior to surgery, colonoscopy, or a barium enema to cleanse the bowel
2. Ingestion of a significant or life-threatening amount of sustained-release medications^{[1, 2, 4]}
3. Ingestion of a significant or life-threatening amount of medications or xenobiotics that are not adsorbed by activated charcoal, or if no other GI decontamination methods are appropriate (eg, iron supplements, lead foreign body)^{[1, 2]}
4. Ingestion of illicit drug packets^{[1, 2]}
5. Ingestion of whole transdermal patches (eg, transdermal fentanyl patch, transdermal clonidine patch)^{[5, 6, 7]}

1. Unprotected airway or compromised airway^{[1, 2]}
2. Bowel obstruction, ileus, or perforation^{[1, 2, 8]}
3. Clinically significant GI bleed^{[1, 2]}
4. Intractable vomiting^{[1, 2]}
5. Unstable vital signs^{[1, 2, 9]}
6. Signs of leakage of illicit drug packets (eg, tachycardia, hypertension, hyperthermia in a patient who has ingested cocaine packets); surgical consult should be obtained in this circumstance^{[1, 10]}

Whole-bowel irrigation and activated charcoal interactions

Either whole-bowel irrigation (WBI) or single-dose activated charcoal (SDAC) is used for GI decontamination. Sometimes WBI is used in conjunction with SDAC to enhance GI decontamination. Many studies done with chlorpromazine,^[11] fluoxetine,^[12] theophylline,^[13] cocaine,^[14] and sustained-release preparations of carbamazepine^[15] revealed that WBI decreases the efficacy of activated charcoal by increasing the rate of desorption of xenobiotics already attached to the activated charcoal when both therapies are used simultaneously or when WBI is used shortly after activated charcoal. Thus, WBI is not recommended when activated charcoal is given, especially if activated charcoal is known to adsorb certain xenobiotics very well.

Two double-blinded randomized control studies, one involving 60 patients^[16] and the other involving 206 patients,^[17] demonstrated that the use of both lidocaine spray and lubricating jelly for the insertion of nasogastric (NG) tubes was superior to the use of lubricating jelly alone. One milliliter of 10% lidocaine solution was sprayed into each nostril, in conjunction with 2 mL of 10% lidocaine solution sprayed into the back of the oropharynx. An NG tube was then lubricated using either lidocaine jelly or KY jelly. These simple steps were shown to significantly reduce patient pain, discomfort, and related adverse events (cough, epistaxis, chest pain, vomit, shortness of breath, dizziness, and epigastric pain).^[17] Moreover, applying lidocaine spay prior to NG tube insertion increased both physicians and nurses’ satisfaction during the procedures.^{[16, 17]}

The images below depict the equipment required.

• 10% lidocaine solution (See image below.)10% lidocaine solution
• 2% Xylocaine jelly or KY jelly for lubrication (See image below.)2% Xylocaine jelly or KY jelly for lubrication
• Nasogastric tube of appropriate size (See image below.)Nasogastric tube.
• Reservoir bag to hold irrigation polyethylene glycol electrolyte solution (PEG-ES) (See image below.)Nasogastric feeding bag (reservoir bag for the irrigation solution).
• PEG-ES (GoLYTELY) (See image below.)Polyethylene glycol electrolyte solution.
• Intravenous (IV) pole to hang the bag of irrigation solution
• Bedside commode (See image below.)Bedside commode.

• Obtain a plain abdominal film to confirm nasogastric (NG) tube placement before administering the irrigation solution.
• The patient should be comfortably seated on the bedside commode.

• Insert a nasogastric tube as described in the eMedicine article Nasogastric Tube.
• Once placement is confirmed, the polyethylene glycol electrolyte solution (PEG-ES) can be administered.
• The efficacy of whole-bowel irrigation (WBI) was not shown to be enhanced by pretreatment with an antiemetic in a study that compared 2 groups, one received 10 mg of oral metoclopramide 30 minutes before WBI and the other received placebo.^[18]
• The solution is administered at a rate of 500 mL/h in children 9 months to 6 years, 1000 mL/h in children 6 to 12 years, and 1500 to 2000 mL/h in adolescents and adults.
• The patient should be seated on a bedside toilet.
• The entire procedure usually takes 4-6 hours.
• Patients often experience nausea and may vomit.

  • The rate of infusion may need to be slowed.
  • Alternatively, an antiemetic may be administered.
• The procedure is stopped once clear rectal effluent is seen or all drug packets have emerged.

Whole-bowel irrigation for bowel preparation prior to colonoscopy

Patients scheduled for outpatient colonoscopy typically are asked to drink PEG-ES at home prior to the procedure in attempt to cleanse the bowel. They are instructed to ingest the solution in one large (usually about 4 L) single dose. However, since 2005, many randomized control trials compared split-dose PEG-ES with the traditional large single dose.^{[19, 20, 21, 22, 23]} The split dose requires patients to drink 2-3 L of PEG-ES the night before, and 1-2 L the day of the colonoscopy. One meta-analysis showed that the split dose of PEG-ES was better than the large single dose with respect to colon cleansing (odds ratio [OR], 3.70; 95% confidence interval [CI], 2.79-4.91; P < .01), patient compliance, and patient willingness to repeat the same bowel preparation (OR 1.76; 95% CI, 1.06-2.91; P<.03).^[24] The authors of the meta-analysis conclude that the use of split dose therapy is superior to single dose and that these changes should beinstituted worldwide.

• If resistance is encountered while inserting the nasogastric (NG) tube into the patient, do not force insertion.
• The following tips may help with insertion of the NG tube:

  • Warm water may help to soften the tip of the NG tube to make insertion easier.
  • Tying a knot at the tip of the NG tube (for about 5 min) helps create a curve that may make insertion easier. Make sure to untie the knot prior to insertion.
  • Curve the tip of the NG tube and place in a cup of ice for several minutes. Insert the stiffened NG tube with the tip initially pointed down. Once the tip enters the oropharynx, rotate the NG tube 180° so that the tip now points posteriorly toward the esophagus.
• Have a commode by the patient's bedside.

• Nausea/vomiting
• Abdominal bloating/cramps
• Unsuccessful nasogastric (NG) tube insertion
• Misplacement of NG tube
• Organ injuries during NG tube insertion
• Despite popular misconception, significant electrolyte abnormalities are not caused by whole-bowel irrigation.