Bowel Preparation Regimens

What are the colorectal cancer screening recommendations for an average-risk patient?

- Age 45-75: colonoscopy every 10 years

- Age 76-85: individualize based on health factors

- Age >85: screening no longer recommended

What diet should patients follow 1 day before colonoscopy?

Low-residue diet

What foods should patients avoid the day before colonoscopy?

- High-fat foods

- High-fiber foods,

- Red or purple dye

What foods should be avoided before colonoscopy?

- Red meat

- Nuts/seeds

- Whole grains

- Vegetables with seeds/skin

- Colorful fruits/juices

- Deep-fried foods

What is the bleeding risk of colonoscopy vs polypectomy?

- Colonoscopy: low-moderate risk

- Polypectomy: moderate-high risk

Which anticoagulant and antiplatelet medications are specifically concerning before colonoscopy?

- Warfarin

- DOACs

- Aspirin

- P2Y12 inhibitors

Why are antihyperglycemics concerning during bowel prep?

Fasting during bowel prep increases the risk of hypoglycemia

Which antihyperglycemics are specifically concerning before colonoscopy?

- Metformin

- Sulfonylureas

- Insulin

Why are GLP-1 receptor agonists concerning before colonoscopy?

They slow bowel motility and may lead to inadequate bowel preparation

What OTC products may need to be avoided before colonoscopy and why?

- Iron darkens stool

- NSAIDs and some herbal supplements may increase bleeding risk

- Fiber supplements increase stool bulk

What are major risk factors for inadequate bowel preparation?

- Cirrhosis

- Parkinson disease

- Dementia

- Diabetes

What factors that slow bowel motility increase the risk of inadequate prep?

- Opioid use

- TCAs

- Gastroparesis

- Constipation

Are any bowel prep regimens clearly superior to the others?

No

What bowel prep volume do guidelines recommend for low-risk patients?

2-L preparations over 4-L preparations

What bowel-prep dosing regimen is recommended?

Split-dose regimen

How is a split-dose bowel prep administered?

First half the night before, second half the morning of the colonoscopy

What is the major advantage of isotonic bowel-prep products?

Low concern for electrolyte imbalance or dehydration

What is the major concern with hypertonic bowel preps?

Higher risk of fluid and electrolyte shifts

Which patients require caution with hypertonic bowel preparations?

Patients with heart failure, kidney dysfunction, or baseline electrolyte abnormalities

What are sulfate-free 4-L PEG-ELS options?

NuLYTELY, GaviLyte-N, TriLyte

How do PEG bowel preparations work?

Poorly absorbed PEG pulls water into the GI tract

What are the major disadvantages of 4-L PEG-ELS?

- Large volume = reduced tolerability

- Sulfate-containing products have a foul taste

What is MoviPrep?

2-L PEG-ELS + ascorbate bowel preparation

What is PLENVU?

A 1-L PEG plus ascorbate bowel preparation and the lowest-volume isotonic prep option

What important contraindication is shared by MoviPrep and PLENVU?

Avoid in glucose-6-phosphate dehydrogenase deficiency because of the ascorbic acid component.

Why should MoviPrep and PLENVU be used cautiously in phenylketonuria?

The contain aspartame

What is unique about PLENVU compared with other isotonic preparations?

It is the lowest-volume isotonic bowel prep

What is the name of the tablet bowel prep containing sodium sulfate, magnesium sulfate, and potassium chloride?

SUTAB

Which patient may prefer SUTAB?

Someone who has not tolerated prep solutions in the past

In which patients should SUTAB be used cautiously?

Patients with kidney dysfunction

What is the name of the liquid bowel prep containing sodium sulfate, potassium sulfate, and magnesium sulfate?

SUPREP

What is the name of the ready-to-drink prep containing sodium picosulfate, magnesium oxide, and citric acid?

CLENPIQ

How does CLENPIQ work?

- Sodium picosulfate → stimulates bowel motility

- Magnesium oxide + citric acid → form ions that pull water into the GI tract

What is a major advantage of CLENPIQ?

Very low prep-solution volume: only 12 oz prep, plus water

Which patients should avoid or use caution with CLENPIQ?

CrCl <30 mL/min

How is OTC PEG-3350 used for bowel preparation?

Mix 238 g PEG-3350 into 2 L of an electrolyte beverage, then take 1 L the night before and 1 L the morning of the procedure

Why should an electrolyte beverage be used with PEG-3350 bowel prep?

PEG-3350 solution alone can cause electrolyte depletion

Which bowel prep should be avoided in renal impairment, heart failure, decompensated cirrhosis, and electrolyte abnormalities?

Magnesium citrate

What adjunctive laxative is often used with PEG-3350 bowel prep?

Bisacodyl 10-15 mg

What dose of simethicone is listed for bowel-prep adjunct use?

320 mg