Two liters of polyethylene glycol-electrolyte lavage solution versus sodium phosphate as bowel cleansing regimen for colonoscopy: a prospective randomized controlled trial

Measurement of serum electrolytes and phosphate after sodium phosphate colonoscopy bowel preparation: an evaluation

Our purpose was to observe the effects of sodium phosphate (NaP) colonoscopy preparation on serum electrolytes, phosphate, and calcium and to identify factors associated with any adverse effects. In an unselected group of 100 consecutive patients attending for out patient colonoscopy, 45% of patients had raised serum phosphate, which was positively correlated with creatinine and age. There was a negative association of phosphate with calcium; 16% of patients had hypocalcemia and 26% had hypokalemia. Patients taking ACE inhibitors, AT2 antagonists, or diuretics were associated with hyperphosphatemia. Significant electrolyte and metabolic disturbance from colonoscopy preparation has been shown with NaP preparation, without overt clinical effects. We recommend that elderly patients and those with significant comorbidity have their electrolytes and calcium measured, and diuretics and ACE inhibitors stopped, before NaP administration. Endoscopy units should be alert for patients who might be suffering from electrolyte disturbance postpreparation and be prepared to measure their electrolytes.

Efficacy of bowel preparation with the use of a prepackaged, low fibre diet with a low sodium, magnesium citrate cathartic vs. a clear liquid diet with a standard sodium phosphate cathartic

BACKGROUND

A colon free of faecal residue is required for accurate diagnostic colonoscopy. Patient tolerance of his/her colonoscopy cathartic regimen affects patient compliance and willingness to undergo repeated examinations.

AIM

To determine whether a meal could be consumed during standard bowel preparation.

METHODS

This was a randomized, endoscopists' blinded comparison of the tolerability and efficacy of a prepackaged, low-residue diet (NutraPrep) combined with the LoSo Prep bowel cleansing system, which contains magnesium citrate, bisocodyl tablets and a bisocodyl suppository (NP-LS regimen), compared with a clear liquid diet and a double-dose sodium phosphate (Fleet Phospho-soda) regimen (2F regimen). Outcome measures included efficacy of bowel preparation, patient preparation tolerability, side-effects and patient safety.

RESULTS

A total of 506 patients completed the study, 222 randomized to 2F and 284 to NP-LS. The NP-LS regimen resulted in significantly better colon cleansing in terms of the proportion with good or excellent results (P = 0.025) and in significantly better patient tolerance and willingness to repeat the cathartic preparation (P < 0.01).

CONCLUSION

The NP-LS regimen proved superior to the 2F regimen.

Effects of hyperosmolar agents--lactulose, lactitol, sodium phosphate and polyethylene glycol--on cecal coliform bacteria during traditional bowel cleansing: an experimental study in rats

Mechanical bowel cleansing is considered to be necessary prior to colorectal surgery, some radiological or endoscopic procedures, and for fecal disimpaction. Traditional bowel cleansing (TBC) with cathartics and enemas is a method of mechanical bowel cleansing for patients who have restrictive factors for whole-bowel irrigation (WBI), such as excessive fecal impaction, cardiac, hepatic or renal disorders. In this experimental study, TBC with hyperosmolar agents was evaluated in terms of their effects on colonic flora and bacterial translocation (BT). Sprague-Dawley rats were divided into 6 groups. The animals, except controls, were not fed for 72 h but received tap water ad libitum. During this period, lactulose, lactitol, sodium phosphate (NaP), polyethylene glycol 3350 (PEG3350) and physiological saline gavages were administered to the rats in groups 1-5, respectively, once a day. All animals except controls (group 6) received enemas with 15 ml of warm saline twice a day. The cecum, mesenteric lymph nodes (MLNs) and portal vein blood were sampled for microbiological and histopathological analysis. The highest level of coliform bacterial overgrowth and BT to MLNs were observed in the lactulose group, although the others, except the saline and control groups, also caused some degree of BT. Portal vein cultures were negative for all groups. Histopathological damage was not associated with cecal bacterial count and BT. As a result of this study, PEG3350 seems to be safer and more effective than lactulose, lactitol and NaP during TBC.

Oral sodium phosphate solution: a review of its use as a colorectal cleanser

Oral sodium phosphate solution (Fleet Phospho-soda, Casen-Fleet Fosfosoda is a low-volume, hyperosmotic agent used as part of a colorectal-cleansing preparation for surgery, x-ray or endoscopic examination. The efficacy and tolerability of oral sodium phosphate solution was generally similar to, or significantly better than, that of polyethylene glycol (PEG) or other colorectal cleansing regimens in patients preparing for colonoscopy, colorectal surgery or other colorectal-related procedures. Generally, oral sodium phosphate solution was significantly more acceptable to patients than PEG or other regimens. The use of this solution should be considered in most patients (with the exception of those with contraindications) requiring colorectal cleansing. PHARMACOLOGICAL PROPERTIES: After the first and second 45 mL dose of oral sodium phosphate solution, the mean time to onset of bowel activity was 1.7 and 0.7 hours and the mean duration of activity was 4.6 and 2.9 hours. Bowel activity ceased within 4 hours of administration of the second dose in 83% of patients. Elevations in serum phosphorus and falls in serum total and ionised calcium from baseline occurred during the 24 hours after administration of oral sodium phosphate solution in seven healthy volunteers. These changes were not associated with significant changes in clinical assessments. The decrease in serum potassium levels after administration of oral sodium phosphate solution was negatively correlated with baseline intracellular potassium levels.

THERAPEUTIC USE

A regimen that administered the first dose of sodium phosphate on the previous evening and a second dose on the morning of the procedure (10-12 hours apart) was significantly more effective than PEG-based regimens for colorectal cleansing in preparation for colonoscopy, sigmoidoscopy or colorectal surgery. A regimen that administered both doses of oral sodium phosphate on the day prior to the procedure offered no colorectal cleansing advantage over PEG-based regimens and was significantly less effective than an oral sodium phosphate solution regimen that administered one dose on the previous evening and a second dose on the morning of the procedure. Oral sodium phosphate solution was generally as effective as other colorectal cleansing solutions (including magnesium citrate-containing regimens with sodium picosulfate). The direct costs of a diagnostic colonic examination with oral sodium phosphate solution were less than those with PEG (US465 dollars vs US503 dollars per patient; 1995 values), according to data from a US study. Oral sodium phosphate solution was significantly more effective than a commercially available tablet formulation as a colorectal cleanser prior to colonoscopy (data from one study only).

TOLERABILITY

Oral sodium phosphate solution administered as two 45 mL doses (generally 10-12 hours apart) was well tolerated in well designed trials in which adults with major comorbid conditions were excluded. Sodium phosphate-associated adverse events were mostly gastrointestinal (including abdominal pain/cramping, abdominal fullness and/or bloating, anal or perianal irritation or soreness, nausea, vomiting or hunger pains), although dizziness, weakness/fatigue, thirst, chest pain, chills, headache and sleep loss were also reported. Faecal incontinence was commonly reported in the elderly. Three doses (administered 10 minutes apart) of 15 mL of oral sodium phosphate solution, each diluted in 250 mL of clear fluid was associated with less vomiting than one 45 mL dose of the solution diluted in 250 mL of clear fluid (data from one study). In patients without major comorbid conditions, oral sodium phosphate has been associated with transient and clinically inconsequential changes in intravascular volume and electrolyte disturbances. Serious electrolyte disturbances have been associated with oral sodium phosphate administration in patients in whom sodium phosphate is contraindicated or should be use with caution (the elderly and those with bowel obstructions, small intestinal disorders, poor gut motilderly and those with bowel obstructions, small intestinal disorders, poor gut motility, renal insufficiency, cardiovascular disease or taking concomitant medication) or in patients ingesting more than the recommended dosage. Changes in the colonic mucosa have been reported in patients treated with oral sodium phosphate solution; however, the exact role of this agent in the appearance of these changes has not been fully clarified. The tolerability profile of oral sodium phosphate solution was similar to, or significantly better than, that of PEG or other colorectal cleansing regimens. Oral sodium phosphate solution was generally significantly more acceptable than PEG or other colorectal cleansing regimens. Oral sodium phosphate solution had similar tolerability, but was considered to be more acceptable than commercially available oral sodium phosphate tablets prior to colonoscopy (data from one study).

A quality improvement project comparing two regimens of medication for colonoscopy preparation

As part of an ongoing performance evaluation and Quality Improvement (QI) program at the U. S. National Naval Medical Center in Bethesda, Maryland, two bowel preparations that were concurrently in use (Fleet Phospho-soda and Colyte/Dulcolax) were evaluated for patient tolerance and preference, efficacy, and cost. Anonymous patient questionnaires were distributed during a three-phase assessment that took place over an 18-month period. This approach identified preconceived ideas regarding bowel preparations and contributed to development of objective information regarding the bowel preparations currently available. The outcome of this QI project altered the previous routine and resulted in the adoption of Fleet Phospho-soda as the preferred medication for colon preparation prior to colonoscopy, based on superior bowel cleansing as judged by the physicians, higher patient preference and compliance, similar tolerance, and lower cost.

Effect of four-day psyllium supplementation on bowel preparation for colonoscopy:A prospective double blind randomized trial [ISRCTN76623768]

BACKGROUND

Patients with new onset constipation or presumed hemorrhoid bleeding frequently require the use of both fiber supplements and diagnostic colonoscopy. We sought to determine whether preliminary fiber supplementation would alter the tolerability or efficacy of a standard bowel preparation for colonoscopy

METHODS

A prospective, double blind, randomized trial was designed to compare a short course of a psyllium-based supplement versus placebo prior to a colon lavage. Patients were given an unlabeled canister of powder, and instructed to take 1 tablespoon with 8 oz of water bid for 4 days before colonoscopy. A 4-liter polyethylene based glycol lavage was self-administered over 4 hours on the day prior to colonoscopy. A questionnaire on pre-study bowel habits and side effects was completed. Efficacy of the preparation was visually evaluated on a pre-determined scale.

RESULTS

There were no significant differences between the two groups in gender, race, age, pre-study stool frequency or consistency. Tolerability was equivalent but efficacy of the bowel preparation was worse in the psyllium group compared to placebo (P < 0.05).

CONCLUSIONS

In non-constipated patients psyllium based fiber supplementation should not be initiated in the few days prior to endoscopy using a polyethylene glycol preparation.