From the Guidelines
You should hold off on bowel preparation for colonoscopy when liver function tests show severe abnormalities, typically when transaminases (ALT/AST) exceed 5 times the upper limit of normal or when there is evidence of decompensated liver disease, as suggested by the most recent study 1. This approach is based on the latest recommendations for detection, assessment, and management of suspected drug-induced liver injury during clinical trials in oncology patients.
- The study 1 highlights the importance of considering the degree of abnormality in liver function tests when deciding whether to proceed with bowel preparation.
- It also notes that using multiples of individual baselines to define action levels in patients with abnormal ALT at baseline may not be adequate, and that 'mapping' the thresholds used for patients with normal baselines onto different categories of baseline abnormality may be a more suitable approach.
- The study 1 provides an algorithm for monitoring and management of possible hepatocellular DILI in phase 2-3 NASH clinical trials in patients with normal or elevated baseline ALT, which can be used as a reference for determining the severity of liver function abnormalities.
- The study 1 classifies the severity of abnormal aminotransferase as mild, moderate, or severe, and provides guidance on the interpretation of liver function tests, including the use of ALT and AST levels to assess liver damage.
- The study 1 provides guidelines on the management of abnormal liver blood tests, including the use of non-invasive algorithms such as the AST to ALT ratio to assess the risk of significant fibrosis in adults with abnormal liver blood tests. Overall, the decision to hold off on bowel preparation should be based on a thorough evaluation of the patient's liver function and the potential risks and benefits of the procedure, and should always be made in consultation with a hepatologist.
From the Research
Liver Function Test Abnormalities
The decision to hold off on prep due to liver function test abnormalities depends on various factors, including the severity of the abnormality and the underlying cause of the liver disease.
- The study 2 suggests that in advanced liver disease, drugs with predominant hepatic metabolism and/or excretion, particularly those with a narrow therapeutic index, should be used with caution.
- Another study 3 classifies liver diseases as hepatocellular, cholestatic, and infiltrative, and provides guidelines for interpreting liver test results, including transaminase increases and alkaline phosphatase levels.
Interpretation of Liver Test Results
The interpretation of liver test results is crucial in determining the severity of liver disease and the need to hold off on prep.
- The study 3 states that hepatocellular disease is characterized by transaminase increases greater than 5 times the upper limit of normal, with alkaline phosphatase levels usually increased less than 2 to 3 times the upper limit of normal.
- The study 4 notes that a broad array of biochemical tests are used to assess the many functions of the liver and to evaluate patients with suspected or established liver disease.
Specific Guidelines
There are no specific guidelines provided in the studies for the exact level of liver function test abnormality at which to hold off on prep.
- However, the study 5 recommends annual liver function tests throughout the lifespan, starting at the age of 10 years, for girls and women with Turner syndrome, and suggests that a prospective and more comprehensive study of liver function in younger patients with Turner syndrome is needed.
- The study 6 reports a case of abnormal serum transaminases following therapeutic doses of acetaminophen in a healthy individual, highlighting the importance of careful consideration of liver function test results in patients with abnormal LFTs 2, 6.