Should patients undergo a clear liquid diet and bowel preparation the day before a capsule endoscopy for investigating a source of gastrointestinal bleeding?

From the Guidelines

Recommendation for Capsule Endoscopy Preparation

Patients should undergo a clear liquid diet for at least 24 hours prior to a capsule endoscopy to investigate a source of gastrointestinal bleeding, as this helps minimize residual debris and optimize visualization 1.

• A bowel preparation with a polyethylene glycol (PEG) solution is also recommended to further reduce intestinal contents and improve capsule transit, although the specific details of this preparation, such as dose and timing, are not specified in the provided evidence 1.
• Additionally, it is advisable for patients to avoid taking iron supplements for a period before the procedure to prevent interference with the capsule's optical sensors, but the exact duration is not clearly stated in the given studies.
• The use of capsule endoscopy in the investigation of gastrointestinal bleeding is supported by guidelines that highlight its utility in visualizing the small intestine and aiding in the diagnosis of various disorders, including obscure gastrointestinal bleeding 1.
• While the evidence does not provide a uniform protocol for bowel preparation, the principle of minimizing intestinal contents to improve the efficacy of the capsule endoscopy is a key consideration in clinical practice 1.

From the Research

Bowel Preparation for Capsule Endoscopy

• The optimal bowel preparation protocol for capsule endoscopy is yet to be defined, with various studies comparing different regimens 2, 3, 4, 5.
• A study comparing four purgative regimens found that intraprocedure purgative regimens reduced small-bowel transit time, enhanced visualization, improved diagnostic yield, and increased angioectasia detection 2.
• Another study found that preparation with 2 L of polyethylene glycol (PEG) before small bowel capsule endoscopy may improve small bowel cleansing and the quality of visualization, while simethicone may further reduce intraluminal bubbles 3.
• A study comparing linaclotide and PEG for bowel preparation found that single-dose linaclotide 1 h before capsule endoscopy was equally effective as PEG in terms of visualization and transit time 4.
• A retrospective review of 284 patients found that 4 liters of clear liquids for bowel preparation resulted in significantly higher mean image quality scores compared to 2 liters of PEG 5.

Clear Liquid Diet

• A clear liquid diet is often recommended as part of the bowel preparation protocol for capsule endoscopy 3, 5.
• A study found that a 24-hour liquid diet and overnight fasting resulted in acceptable small bowel cleansing in 65% of patients 3.
• Another study found that 4 liters of clear liquids resulted in higher mean image quality scores and more studies with adequate preparation compared to 2 liters of PEG 5.

Diagnostic Yield

• The diagnostic yield of capsule endoscopy can be influenced by the bowel preparation protocol used 2, 6, 4.
• A study found that the overall diagnostic yield of patients receiving intraprocedure purgatives was superior to those receiving bowel preparation the night before capsule endoscopy 2.
• Another study found that capsule endoscopy had a high diagnostic yield and safety in the investigation of obscure gastrointestinal bleedings, with a diagnostic yield of 73.8% 6.