Why dairy products should not be consumed before a colonoscopy
Feb 21, 2025
Source: Cainiu Health
Dr. Shen Yonghua
Introduction
Under normal circumstances, the reasons why dairy products should not be consumed before a colonoscopy include their digestion and absorption characteristics, the tendency to produce gas leading to intestinal gas accumulation, residue that may affect the field of view, the potential to cause intestinal dysfunction, and interactions with bowel cleansing medications. To ensure the accuracy of the colonoscopy and patient comfort, patients should strictly follow their doctor's dietary instructions.
Generally, there are several reasons why dairy products should not be consumed before a colonoscopy, including their digestion and absorption characteristics, tendency to produce gas leading to intestinal gas accumulation, residue that may affect visualization, potential to cause intestinal dysfunction, and interactions with bowel cleansing medications. The specific details are as follows:
1. Digestion and Absorption Characteristics
The proteins in dairy products are mainly casein and whey protein, and the fat exists in the form of milk fat globules. These components are digested relatively slowly in the gastrointestinal tract. Casein, in particular, forms clots under the action of gastric acid, increasing the difficulty of digestion and possibly remaining in the intestines for a longer time, which affects the effectiveness of intestinal cleansing.
2. Gas Production Leading to Intestinal Gas Accumulation
Some dairy products contain lactose. Some individuals lack lactase, the enzyme needed to fully digest and break down lactose. When lactose is fermented by bacteria in the intestines, it produces a large amount of gas, causing intestinal gas accumulation. This not only causes discomfort such as bloating but also interferes with the doctor's observation of the intestinal mucosa during colonoscopy. The gas-generated artifacts may obscure intestinal lesions, affecting the accuracy of the examination results.
3. Residue Affecting Visualization
The fat components in dairy products may adhere to the surface of the intestinal mucosa, forming a layer of oily film. During colonoscopy, this oily film affects the endoscope's ability to visualize the intestinal mucosa, making it difficult for the doctor to clearly see fine structures and lesions such as polyps and ulcers, thereby increasing the risk of missed diagnosis.
4. Potential to Cause Intestinal Dysfunction
For individuals with sensitive intestines, dairy products may irritate the intestines, causing increased peristalsis or spasms, leading to symptoms of intestinal dysfunction such as diarrhea and abdominal pain. This may complicate the condition of the intestine, making bowel preparation less effective and possibly affecting the operation and interpretation of the colonoscopy results.
5. Interaction with Bowel Cleansing Medications
Prior to a colonoscopy, it is usually necessary to take bowel cleansing medications to clean the intestines. Components in dairy products may interact with these medications, affecting drug absorption and excretion. For example, calcium in dairy products may combine with components of the cleansing medication to form insoluble complexes, reducing the efficacy of the medication and thus failing to achieve the desired bowel cleansing effect.
To ensure the accuracy of the colonoscopy and the patient's comfort, patients should strictly follow the dietary instructions provided by their doctor.
