Optimal Laxatives for Oral Colonoscopy Bowel Preparation: from High-volume to Novel Low-volume Solutions / 대한소화기학회지

Optimal bowel preparation is essential for a more accurate, comfortable, and safe colonoscopy. The majority of postcolonoscopy colorectal cancers can be explained by procedural factors, mainly missed polyps or inadequate examination. Therefore the most important goal of optimal bowel preparation is to reduce the incidence of colorectal cancer. Although adequate preparation should be achieved in 85–90% or more of all colonoscopy as a quality indicator, unfortunately 20–30% shows inadequate preparation. Laxatives for oral colonoscopy bowel preparation can be classified into polyethylene glycol (PEG)-electrolyte lavage solution, osmotic laxatives, stimulant laxatives, and divided into high-volume solution (≥3 L) and low-volume solution (<3 L). The updated 2019 European Society of Gastrointestinal Endoscopy (ESGE) guideline is broadly similar to the 2014 American Society for Gastrointestinal Endoscopy (ASGE) recommendations and reaffirms the importance of split-dosing. However, new ESGE guideline, unlike the 2014 ASGE recommendation, suggests the use of high volume or low volume PEG-based regimens as well as that of non-PEG based agents that have been clinically validated for most outpatient scenarios. For effective, safe, and highly adherent bowel preparation, physicians who prescribe and implement colonoscopy should properly know the advantages and limitations, the dosing, and the timing of regimens. Recently many studies have attempted to find the most ideal regimens, and more convenient, effective, and safe regimens have been developed by reducing the dosing volume and improving the taste. The high tolerability and acceptability of the new low-volume regimens suggest us how we should use it to increase the participation of the national colorectal cancer screening program.

Acute Gastric Injury Caused by Undissolved Sodium Picosulfate/Magnesium Citrate Powder

Sodium picosulfate/magnesium citrate (SPMC) is a widely used oral bowel cleansing agent considered to be relatively safe. However, partially dissolved or undissolved SPMC powder may cause severe injuries of the esophagus and stomach. We report a very rare case of acute gastric injury without esophageal damage caused by the ingestion of undissolved SPMC powder. A 69-year-old man experienced epigastric pain after swallowing SPMC powder without dissolving it in water in preparation for a screening colonoscopy. He realized his mistake immediately and subsequently drank 2 L of water. The esophagogastroduodenoscopy conducted after 12 hours indicated an acute gastric ulceration without injury of the esophagus or duodenum. The endoscopy conducted after 6 weeks of oral proton pump inhibitor treatment showed healing of the gastric injury. This suggested that drinking large amounts of water after ingesting partially dissolved or undissolved SPMC powder can prevent serious esophageal injury, but offers no preventive benefit for acute gastric injury.

Split-dose Bowel Preparation for Colonoscopy: 2 Liters Polyethylene Glycol with Ascorbic Acid versus Sodium Picosulfate versus Oral Sodium Phosphate Tablets / 대한소화기학회지

BACKGROUND/AIMS: Adequate bowel preparation is an essential factor affecting the visibility of colonic mucosa and safety of related therapeutic interventions. The aim of this study was to assess the efficacy, tolerability, and safety of three bowel preparation agents –2 L polyethylene glycol with ascorbic acid (PEGA), sodium picosulfate magnesium citrate (SPMC), and oral sodium phosphate tablet (NaP)– for morning colonoscopy. METHODS: Here, we analyzed the medical records of patients who had taken bowel preparation agents using the split-dose method and undergone colonoscopy in a single hospital. The efficacy of bowel preparation agents was evaluated using the Ottawa bowel preparation assessment tool. The safety and tolerability of the agents were assessed by measuring the renal function and electrolytes prior to and after the procedure as well as by assessing the self-reported questionnaire. RESULTS: Of the 365 patients (PEGA:163, SPMC: 93, NaP: 109), 98.6% ingested more than 90% of the agents. NaP showed an inferior cleansing efficacy, and serum phosphate elevation was significantly higher in the NaP group. However, the satisfaction score was lowest in the PEGA group. Age (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.92–0.99, p=0.04) and preparation agents (OR of PEGA versus NaP 5.0, 95% CI 2.28–10.97, p<0.001) (OR of SPMC versus NaP 2.73, 95% CI 1.22–6.08, p=0.01) were independently associated with bowel preparation success. CONCLUSIONS: According to our analysis, NaP showed an inferior cleansing efficacy compared with PEGA and SPMC, which may be attributed to the complex administration method and lower water intake. However, large-volume ingestion remains unsatisfactory for patients. Detailed bowel preparation instructions could enhance bowel cleansing efficacy.

Severe Hyponatremia with Mental Change after Ingestion of Picosulfate Sodium/Magnesium Citrate for Bowel Preparation / 대한내과학회지

Picosulfate sodium/Magnesium citrate (PS/MC) is a common bowel cleansing agent for colonoscopy. It is equally effective and better tolerated by patients with regard to taste and volume than polyethylene glycol. However, because of its osmotically active characteristics, PS/MC can cause plasma volume depletion and electrolyte disturbances, such as hyponatremia. Here, we report a case of severe hyponatremia combined with loss of consciousness in a 59-year-old woman following ingestion of PS/MC as bowel preparation for a screening colonoscopy. Upon arrival, serum sodium level was 109 mEq/L and urine osmolality and sodium levels were 393 mOms/Kg and 99 mmol/L, respectively. She was euvolemic and showed normal kidney, thyroid, and adrenal function. Based on these findings, inappropriate anti-diuretic hormone syndrome (SIADH) was diagnosed. She was treated with 3% hypertonic saline and completely recovered without any neurologic sequelae. This case shows that SIADH can be caused by PS/MC (not accompanied by dehydration), even in patients without any underlying renal, heart, or liver diseases.

A Case of Upper Airway and Esophageal Injury after Ingestion of Sodium Picosulfate and Magnesium Citrate for Colonoscopy

Sodium picosulfate and magnesium citrate are widely used low volume bowel cleansing agents considered to be effective and relatively safe. We describe a case of a woman who presented with an upper airway and esophageal injury after ingestion of a sodium picofulfate and magnesium citrate. A 63-year-old woman presented to emergency department complaining of throat pain and hoarseness after ingestion of sodium picosulfate and magnesium citrate as preparation for colonoscopy. This powder is dissolved in a low volume of water. She had ingested the substance that was not completely dissolved. After ingestion, she experienced a burning sensation in the throat. Promptly, neck radiography and computed tomography (CT) were performed. Radiography revealed epiglottis swelling and narrowing airway. Computed tomography demonstrated diffuse soft tissue edema and thickening with increased enhancement in the upper airway and entire esophagus. She was admitted and treated with parenteral nutrition, intravenous proton pump inhibitor, empirical antibiotics, and steroids. Nine days after the admission, she underwent an esophagogastroduodenoscopy (EGD). Esophageal multiple ulcerative lesions with exudate were observed. Twelve days after admission, she was discharged from the hospital with improvement of pain in her throat and toleration to a solid diet.

Upper airway obstruction resulting from acute mucosal injury induced by direct ingestion of sodium picosulfate/magnesium citrate powder

A 59-year-old man presented to the emergency department with a chief complaint of sore throat after swallowing sodium picosulfate/magnesium citrate powder for bowel preparation, without first dissolving it in water. The initial evaluation showed significant mucosal injury involving the oral cavity, pharynx, and epiglottis. Endotracheal intubation was performed for airway protection in the emergency department, because the mucosal swelling resulted in upper airway compromise. After conservative treatment in the intensive care unit, he underwent tracheostomy because stenosis of the supraglottic and subglottic areas was not relieved. The tracheostomy tube was successfully removed after confirming recovery, and he was discharged 3 weeks after admission.

Acute Hyponatremia With Seizure and Mental Change After Oral Sodium Picosulfate/Magnesium Citrate Bowel Preparation

Sodium picosulfate/magnesium citrate (Picolight Powder), which is used as a bowel preparation for the colon and the rectum, can cause a severe electrolyte imbalance like hyponatremia. When hyponatremia gets severe or occurs rapidly, it can lead to death due to associated complications. We have experienced a case of hyponatremia associated with seizure and loss of consciousness in a 76-year-old woman, who took sodium picosulfate/magnesium citrate as a bowel preparation for colonoscopy. She was taking thiazide and synthroid for the treatment of hypertension and hypothyroidism, respectively, and she had other underlying medical conditions such as a history of seizure and dementia. Following the diagnosis of hyponatremia, we used an intravenous injection of 3% NaCl to normalize the sodium level in her serum, and her associated symptoms soon disappeared.

The Evolution of Bowel Preparation and New Developments / 대한소화기학회지

Bowel preparation is essential for successful colonoscopy examination, and the most important factor is the bowel preparation agent used. However, selection of a bowel preparation agent invariably involves compromise. Originally, bowel preparation was performed for radiologic and surgical purposes, when the process involved dietary limitations, cathartics, and enemas, which had many side effects. Development of polyethylene glycol (PEG) solution led to substantive advancement of bowel preparation; however, despite its effectiveness and safety, the large volume involved, and its salty taste and unpleasant odor reduce compliance. Accordingly, modified PEG solutions requiring consumption of lower volumes and sulfate-free solutions were developed. Aqueous sodium phosphate is more effective and better tolerated than PEG solutions; however, fatal complications have occurred due to water and electrolyte shifts. Therefore, aqueous sodium phosphate was withdrawn by the US Food and Drug Administration, and currently, only sodium phosphate tablets remain available. In addition, oral sulfate solution and sodium picosulfate/magnesium citrate are also available, and various studies have reported on adjunctive preparations, such as hyperosmolar or stimulant laxatives, antiemetics, and prokinetics, which are now in various stages of development.