We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is Lactulose Syrup?

By Jacquelyn Gilchrist
Updated May 17, 2024
Our promise to you
WiseGEEK is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGEEK, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Lactulose syrup is a type of sugar that may be used to treat chronic constipation, and is also prescribed to prevent portosystemic encephalopathy, which is a possible complication of advanced liver disease. This product, which is a synthetic sugar, creates a more acidic environment in the patient's intestines. The end result is that the stool is softened and the levels of ammonia in the blood are reduced.

Portosystemic encephalopathy is a condition in which the patient becomes confused, suffers from altered consciousness, and can fall into a coma. It is a result of advanced liver cirrhosis, and if it is not treated, it can be fatal. Doctors may prescribe lactulose syrup to help prevent this condition because it removes ammonia from the blood and transports it into the colon. Excess levels of ammonia can then be excreted out of the body.

This product also works to alleviate constipation because the body does not readily absorb the syrup. Instead, bacteria breaks it down in the intestines, where it turns into lactic acid. This helps attract more water into the intestines, which softens the stool. Patients may find relief of chronic constipation within 48 hours of ingesting this syrup.

Dosage instructions may vary, but patients will typically be prescribed one dose daily to treat constipation, and three to four doses daily to treat liver cirrhosis. If the patient finds the taste unpleasant, he may mix the syrup with water or fruit juice. He should also consume plenty of water with each dose. A high-fiber diet is recommended to increase the effects of lactulose syrup.

Before using this medication to treat constipation or prevent complications of liver disease, patients should disclose their other medical conditions. Women who are pregnant or breastfeeding should discuss the potential risks with their doctors. Lactulose syrup may be contraindicated for use by those who require a low-lactose diet. Diabetics should check their blood sugar often and call their doctors if they experience excessive thirst or urination, or a fruity odor on their breath. These are typical symptoms of hyperglycemia, or high blood sugar.

In addition, if the patient intends to undergo surgery or diagnostic tests on his colon or rectum, he must inform the surgeon that he is using lactulose syrup. Patients should also discuss their other medications and supplements with their doctors or pharmacists. Lactulose syrup may interact with antacids, other laxatives, diabetes medicines and some antibiotics, such as neomycin.

Some side effects may occur, such as bloating, diarrhea, and minor abdominal cramps. Nausea, vomiting, and belching have also been reported. Patients should contact their doctors if they experience faintness, severe diarrhea, or severe weakness, along with severe abdominal pain.

WiseGEEK is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

By bear78 — On Mar 16, 2014

I suffered from a back injury recently and had to receive many pain relieving injections. Unfortunately, one side effect of the injections is constipation. Although I don't normally have any problems with bowel movements, I developed a severe constipation due to my treatment.

My doctor prescribed me lactulose syrup in addition to glycerin suppositories. The two in combination worked very well and resolved my constipation within the same day. I think that lactulose syrup is a safer alternative to other laxatives.

By candyquilt — On Mar 16, 2014

@burcinc-- Although I am diabetic, I did use lactulose syrup once and it was effective. I did not experience any dramatic change in my blood sugar, but I used a low dose.

As long as you check your blood sugar regularly and adjust your medication or insulin, I think you will be fine. You might want to check with your doctor just in case though.

By burcinc — On Mar 15, 2014

I have diabetes and I realize that lactulose syrup may be problematic for me. However, it was recommended by a friend who uses it for constipation. I'm not sure if I should give it a try or not. Other laxatives have not been working for me.

By Logicfest — On Mar 13, 2014

Is this regarded as a short-term solution to constipation or do people use it long-term in some cases?

There are people out there who swear that a glass or two of prune juice daily is a good long-term solution. That may be worth trying for those who have trouble with constipation -- it's a more "natural" solution if it works.

WiseGEEK, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGEEK, in your inbox

Our latest articles, guides, and more, delivered daily.