Innovative schemes of colonoscopy bowel preparation with oral lactulose: Optimizing traditional standards to improve colonoscopy quality

Table 1 Comparative analysis of the main agents for colonoscopic preparation

	Mechanism of action	Adverse events	Advantages	Limitations	Administration scheme
Oral Lactulose	Non-absorbable disaccharide fermented by colonic bacteria producing an increase in osmotic pressure and stimulating peristalsis	Nausea; Vomiting; Flatulence	Very low volume regimen for colonoscopic preparation. Good tolerability. Low cost Does not produce significant electrolyte alterations. Safe in patients with comorbidities	Little scientific evidence for its use in colonoscopic preparation	Single dose on the same day of the procedure (6 hours before the colonoscopy); 200 mL of lactulose diluted in 600 mL of water + simethicone
Sodium picosulfate + magnesium citrate	Diphenylmethane type stimulant laxative that after being hydrolyzed by colonic bacteria in its active form directly stimulates the submucosal plexus of Meissner in the colon, causing increased colonic motility and decreased reabsorption of water and electrolytes	Nausea; Vomiting; Headache	Low volume regimen for colonoscopic preparation. Good tolerability	High cost; Contraindicated in severe kidney failure (due to magnesium content)	Split doses: One dose the night before and the other the morning of the procedure; Each dose followed by at least 500 mL of clear liquids
Magnesium citrate	Osmotic salt that produces an increase of the intraluminal osmotic pressure in the colon inducing a dragging of water into the bowel lumen and increased motility	Contraindicated in kidney failure	Good tolerability; Low cost	Little scientific evidence for its use in colonoscopic preparation	Split doses: One dose the night before (300 mL) and the other the morning of the procedure (300 mL); Each dose followed by at least 250 mL of clear liquids
Sodium phosphate (NaP)	Hyperosmotic laxative that attracts water into the bowel lumen stimulating peristalsis	Hyperphosphatemia Hypocalcemia; Hypokalemia; Cardiac arrhythmias Phosphate nephropathy	Low volume regimen for colonoscopic preparation. Good tolerability; Fast action	Contraindicated in kidney failure; Congestive heart failure; Liver cirrhosis	Split doses: One dose the night before (45 mL) and the other the morning of the procedure (45 mL); Each dose followed by at least 500 mL of clear liquids
Polyethylene glycol	Non-absorbable inert polymer producing water retention at the intraluminal colonic level and increased peristalsis	Nausea; Vomiting; Abdominal distention	Does not produce significant electrolyte alterations. Safe in patients with comorbidities	Requires high volume intake; Unpleasant taste	Split doses: One dose the night before (2 L) and the other the morning of the procedure (2 L); Low volume alternatives can be combined with other available agents

Table 2 Comparative table of world-wide outcomes in colonoscopic preparation using oral lactulose

Ref.	Boston bowel preparation score	Colorectal adenoma detection rate	Inadequate bowel preparation	Side effects	Disagreeable flavor	Satisfactory overall experience
Aliaga Ramos et al[31]	8.36 ± 1.09	59.5% (66/111)	1.8% (2/111)	46.8% (52/111)	3.6% (4/111)	62.2% (69/111)
Wenqi et al[27]	7.19 ± 1.19	50.0% (100/200)	Not specified	6.5% (13/200)	Not specified	Not specified
Jagdeep et al[29]	6.25 ± 0.786	Not specified	Not specified	50% (10/20)	10% (2/20)	Not specified
Li et al[33]	7.95 ± 1.40	30.7% (27/88)	Not specified	39.7% (35/88)	0%	8.91 ± 1.34