What is Laxative: Uses, Warnings & Interactions

If you use a laxative without a doctor’s prescription, follow the dosage instructions printed on the package.

• Do not take larger doses than recommended.

• Do not take doses more frequently than recommended.

If you are using a laxative under the advice of a healthcare provider, follow the provider’s instructions carefully. 

Tablets should be swallowed whole with a glass of water.

• Fiber tablets should always be swallowed with a full glass of water to prevent choking.

Laxative powders, including fiber, should always be dissolved in a full glass (eight ounces) of water, juice, soda, coffee, or tea before swallowing. 

• If the instructions allow, doses can be measured using a measuring cup, measuring spoon, or the cap.

• Do not eat the powder.

When taking liquid laxatives, measure the liquid with a measuring spoon, oral syringe, medicine cup, or cap if the instructions allow it.

Laxative suppositories are inserted into the rectum only. Do not take them by mouth.

• Wash your hands.

• Inserting the suppository is more comfortable if you dip the tapered end into a water-based lubricant or moisten the entire suppository with cold water.

• Lie on your side and gently insert the suppository tapered end first into your rectum with your finger.

• Make sure the blunt end passes completely through the sphincter.

• If the suppository comes out, insert it more deeply into the rectum.

• Lie still for 15–30 minutes—the time will vary depending on the product.

• Wash your hands.

Laxative enemas are used only in the rectum. Do not take them by mouth.

• Before using the enema, lubricate the anus with petroleum jelly or a water-based lubricant.

• Lie on your side and gently insert the enema tip into your rectum.

• Squeeze all the liquid out of the enema bottle or container.

• Wash your hands.

Laxatives should cause you to have a bowel movement within 15 minutes to 1 hour.

• Enemas or suppositories usually work in less than 30 minutes.

• Laxatives that should be taken at bedtime usually take several hours to work.

• Sometimes, this medicine may take two days or longer to help you have a bowel movement.

Bowel prep laxatives will come with an instruction sheet from the clinic, hospital, or doctor.

• Read the instructions carefully.

• Buy all the supplies you need as soon as possible. 

• If the laxative requires mixing, wait until the morning before the procedure.

• Most people will start taking their laxatives the day before the procedure.

• Some people may need to take a laxative two days before the procedure. If this is the case, a healthcare provider will give you instructions.

• If the laxative needs mixing, do this as soon as possible, the morning before the procedure.

• Start taking doses as instructed at the scheduled time.

• Follow the dosing schedule. Do not miss doses.

• You should drink fluids throughout the day. Your instructions will include a list of fluids you can drink.

If you miss a dose or forget to take your laxative, take it as soon as you can if you still have problems passing stools. 

• If you are taking two doses a day and it is almost time for your next dose, wait until then to take the medicine and skip the missed dose.

• If you’re taking one dose per day, skip the missed dose if it’s the next day. If you still have symptoms, take that day’s dose.

Some laxatives should be taken at bedtime. 

• You can take a missed dose during the day, but doing so could make it difficult to sleep that night. 

If you miss bowel prep doses, follow the instructions or call a healthcare provider.

• In most cases, you can continue taking the laxative according to the dosing schedule if you can take all the doses scheduled for that day.

• If you miss most or all bowel prep doses the day before a procedure, contact the doctor, clinic, or hospital for advice.

Do not use extra medicine to make up for a missed dose.

No one should use a laxative if they have had an allergic reaction to the laxative or any of the inactive ingredients.

Some laxatives are contraindicated in people with bowel obstruction.

Certain types of laxatives are not appropriate for bedridden patients.

Tell the doctor or other healthcare provider who treats you that you are using a laxative.

Do not take a laxative if you’re pregnant until you’ve talked to a healthcare provider.

• Bulk laxatives are usually okay during pregnancy, but a healthcare provider may ask you to avoid other laxatives.

Do not take a laxative until you’ve talked to a doctor if you have:

• Bowel blockage

• A sudden change in bowel habits that lasts 14 days or longer

• Difficulty swallowing

• Esophageal stricture

• Diverticulitis

• Rectal bleeding

• Recent abdominal pain, nausea, or vomiting

• Other stomach or intestine problems

• Kidney disease

• Liver disease

Stop using laxatives if you experience:

• Rectal bleeding

• Diarrhea that lasts longer than a week

• Severe diarrhea (watery diarrhea or bloody diarrhea)

Some laxatives contain electrolytes such as sodium, magnesium, or phosphates. If you are on a sodium, magnesium, or phosphorus-restricted diet, don’t take these laxatives until you’ve talked to a doctor.

Do not use laxatives for longer than advised in the instructions. 

• Most laxatives should not be used for longer than seven days except under a healthcare provider’s instructions.

• Some laxatives are mild enough to be taken for as long as two weeks.

Do not give laxatives to a child until you’ve consulted with a healthcare provider.

• Some laxatives do have age restrictions. Please read the instructions carefully.

Make sure your healthcare provider knows if you have any type of stomach or intestinal (bowel) problems. These may include diverticulitis, intestinal blockage, rectal bleeding, or moderate to severe stomach pain.

If you are taking prescription medications, ask the prescribing doctor for advice before taking any over-the-counter laxatives. 

Tell any healthcare professional who prescribes new drugs that you are taking a laxative.

To avoid side effects, do not take more than one laxative at a time except under the advice of a healthcare professional.

Some laxatives interfere with the ability of the body to absorb other drugs. This will make those drugs less effective.

• Your healthcare provider can tell you if it’s safe to combine a laxative with other drugs.

• In some cases, you may need to separate laxative doses from other drugs by several hours.

Some drugs cause constipation and will make laxatives less effective at helping you pass stools. In some cases, you might be taking a laxative to help fix medication-induced constipation. Constipation-inducing drugs include:

• Anti-diarrhea drugs

• Opioids

• Tricyclic antidepressants

• Iron supplements

• Some blood pressure medications

For bowl prep laxatives, your instructions may include a list of drugs you must stop taking several days before the procedure, such as:

• Iron supplements or vitamins with iron

• Fiber supplements

• Vitamin E

• Anti-diarrhea medicines