What is an ileal brake (ileus)?

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From the Guidelines

The ileal brake is a physiological mechanism that slows down the movement of food through the gastrointestinal tract when nutrients reach the ileum, and its activation is crucial for optimal digestion and nutrient absorption. This mechanism is mediated by the release of hormones such as GLP-1, PYY, and CCK when nutrients, particularly fats and proteins, are detected in the ileum 1. The ileal brake plays a significant role in controlling food intake by increasing feelings of fullness and reducing hunger, making it a potential target for treating obesity and metabolic disorders. In the context of postoperative care, particularly after abdominal surgery, the ileal brake can be affected, leading to postoperative ileus, a common complication characterized by a temporary cessation of the normal contractions of the bowel muscles 1. To minimize postoperative ileus, measures such as minimally invasive surgery, optimized fluid management, and opioid-sparing analgesia are recommended, as outlined in the ERAS protocols 1. Additionally, early mobilization, early postoperative food intake, and the use of laxatives can help maintain intestinal function and prevent postoperative ileus 1. In patients who present with ileus or gross intestinal edema, early oral intake should be encouraged, with small portions offered initially, especially after right-sided resections and small-bowel anastomosis 1. Overall, understanding the ileal brake mechanism is essential for developing effective strategies to prevent and manage postoperative ileus and promote optimal digestion and nutrient absorption. Key factors that influence the ileal brake include:

  • The type and amount of nutrients present in the ileum
  • The release of hormones such as GLP-1, PYY, and CCK
  • The presence of postoperative ileus or other gastrointestinal complications
  • The use of measures such as minimally invasive surgery, optimized fluid management, and opioid-sparing analgesia to prevent postoperative ileus 1.

From the Research

Definition of Ileal Break

  • The "ileal brake" is a primary inhibitory feedback mechanism that controls the transit of a meal through the gastrointestinal tract to optimize nutrient digestion and absorption 2.
  • It is a neurohormonal response that helps to slow down the movement of food through the small intestine, allowing for better absorption of nutrients.

Function of Ileal Break

  • The ileal brake helps to regulate the transit of food through the gastrointestinal tract, preventing rapid movement of food into the colon 2.
  • It plays a crucial role in preventing malabsorption and impaired drug bioavailability, which can manifest as diarrhea and malnutrition.

Relationship to Intestinal Obstruction

  • Intestinal obstruction can occur due to various causes, including adhesions, malignancy, and herniation 3, 4.
  • The ileal brake can be affected in cases of intestinal obstruction, leading to impaired nutrient absorption and malnutrition.

Clinical Significance

  • Understanding the ileal brake is essential for the treatment of chronic diarrhea, malnutrition, and drug malabsorption 2.
  • The ileal brake can be influenced by various factors, including nutrition and gut health, and its dysfunction can lead to various pathologic states.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The ileal brake: a fifteen-year progress report.

Current gastroenterology reports, 1999

Research

Intestinal Obstruction: Evaluation and Management.

American family physician, 2018

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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