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Treatment Name: Lactulose

Lactulose is a Supportive Care Therapy for Constipation

How does lactulose work?

Lactulose is designed to prevent your intestines from absorbing some of the water you drink. When extra water is kept within the intestines, it softens the stool and stimulates the intestines, which produces a bowel movement.

What are lactulose goals of therapy?

Lactulose is taken to relieve occasional constipation. It is commonly taken on an as needed basis with the goal of treating constipation.

Other names:  Enulose, Kristalose, Constulose, Generlac


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How is lactulose taken for constipation?

  • Usual starting dose: 1 to 2 tablespoons (15 to 30 mL) oral solution by mouth once daily

Lactulose is commonly taken at home on an as needed basis to treat constipation to maintain normal, regular bowel movements daily or every other day.

Store lactulose at room temperature (68-77°F).

Side Effects

What are the most common side effects from lactulose?

In the prescribing label information (lactulose package insert), the most commonly reported side effects from lactulose are shown here:

  • Stomach cramps
  • Stomach pain
  • Nausea
  • Vomiting
  • Belching

Lactulose is not absorbed into the blood stream and generally considered safe when taken by pregnant women for short-term use; however, it should be only used in pregnant women if the potential benefits to the mother outweigh any potential risks to the unborn baby.

Note: The exact percentages of patients that will experience lactulose side effects is unknown because it has been used under widely varying patient populations in a variety of clinical trials.

Side effect videos Side Effect Videos
Nausea and VomitingNausea and VomitingPainPain


How often is lactulose monitoring needed?

Labs (blood tests) are usually not necessary to start or continue lactulose therapy.

How often is lactulose imaging needed?

Imaging may be checked if there is concern of a small bowel obstruction (SBO) or blockage. Imaging may include: Abdominal X-ray, or CT scan of the abdomen and pelvis.

How might lacutlose blood test results/imaging affect treatment?

Depending upon the results, your doctor may advise to continue lactulose as planned, add additional laxatives, place you on “bowel rest” (nothing by mouth until the obstruction clears), or switch to an alternative therapy for constipation.

Questions to Ask Your...

A better understanding of your treatments will allow you to ask more questions of your healthcare team. We then hope that with the answers, you will get better results and have greater satisfaction with your care. Because we know it's not always easy to know what questions to ask, we've tried to make it easy for you!

Choose any healthcare provider below to see common questions that you may want to ask of this person. Then, either print each list to bring to your clinic visits, or copy the questions and send them as a message to your healthcare team through your electronic medical record.

ChemoExperts Tips

What are the most important things to know about lactulose?

  • Lactulose solution contains lactose and may increase blood sugar in patients with diabetes
  • If you are receiving chemotherapy, do NOT attempt to use an enema or suppository unless you have discussed this with your doctor. Use of enemas or suppositories could cause a tear in the rectum and may lead to a serious infection
  • Walking helps to stimulate the bowels to move stool down the intestinal tract. A diet high in fiber (found in fruits, vegetables, and whole grains) also helps to maintain a healthy colon (large intestine)
  • It is important to have regular bowel movements, usually once daily or every other day. Otherwise, your small bowel (intestine) may become blocked. Call your doctor if you have not had a bowel movement for 3 days or more, especially if you feel bloated. If you feel pain in your abdomen/belly, feel nauseated, or vomit at any point while constipated, call your doctor immediately
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Lactulose, we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Lactulose. Depending upon your income, they may be able to help cover the cost of:

  • Lactulose

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Lactulose and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

Created: March 31, 2020 Updated: March 31, 2020

What is Constipation?

Many treatment options for constipation exist. Watch our video to learn more about constipation and available treatments.