Medicine for Constipation: OTC, Prescription, and More

By Alicia Wooldridge, MD
Medically reviewed checkmarkMedically reviewed
August 3, 2022

Constipation can range from uncomfortable to making it hard to function in everyday life. 

If it’s been a while since you had a normal bowel movement, over-the-counter (OTC) and prescription treatments can help you find relief.

In this article, first I’ll explain what constipation is.

Then I’ll explore what causes constipation, OTC medicines, prescriptions, and other treatment options.

I’ll conclude with when to seek medical care for constipation.

What Is Constipation?

Constipation means that someone has fewer than four bowel movements per week. 

Stool becomes hard and dry, making it difficult to pass.

Constipation can affect as many as 20% of people from time to time, though some people may be more prone to it. 

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OTC Medicine for Constipation

OTC remedies can help manage infrequent constipation.

Some of these methods can also be preventive, however, do not overuse stimulants, laxatives, or enemas.

Fiber supplements

Taking fiber-based laxatives or supplements can help to promote regularity. 

Also known as bulk-forming laxatives, fiber adds bulk to food as it is digested, helping to increase motility through the gastrointestinal tract and combat problems with hard, dry stools.

If you are very constipated, adding fiber could temporarily make symptoms worse, so if you have never taken a fiber supplement before, start with a small dose. 

It may take a few days before a fiber supplement produces a bowel movement. 

But once you are taking it, it is safe to continue long-term. 

Examples of bulk-forming fiber laxatives include:

  • Psyllium husk (Metamucil, Konsyl)
  • Methylcellulose fiber (Citrucel)
  • Calcium polycarbophil (FiberCon)

Most fiber laxatives are available in powder form that can be mixed with water or juice. 

Some are available in tablet or wafer form. 

When you take fiber supplements, drink plenty of fluids to help reduce possible side effects like bloating and abdominal pain or cramping.

Stool Softeners

Stool softeners help address constipation by adding water and fats into the digestive tract, leading to softer bowel movements that are easier to pass. 

Stool softeners are often recommended after surgical procedures and childbirth to reduce the potential for straining.

Stool softeners typically work within 1-3 days. 

Docusate (Colace, DulcoEase) is a common over-the-counter stool softener. 

It is available in tablet, capsule, or liquid form and is safe for long-term use. 

Discontinue stool softeners if bowel movements become too soft or loose.


Stimulant laxatives force the muscles in the intestine to contract, moving stool through the intestines. 

Oral stimulant laxatives can work within 6-12 hours and are available OTC as liquids or capsules.

Types of stimulant laxatives include:

  • Senna or sennoside (Senokot)
  • Bisacodyl (Dulcolax)

Stimulant laxatives may cause more noticeable side effects like intestinal cramping or pain.

Do not use these long term. 

The body can develop tolerance to their effects and, over time, this can worsen constipation or the ability to naturally pass bowel movements without medication.


Laxatives that help retain water in the intestines are known as osmotics. 

These help soften bowel movements and increase frequency.

Osmotic laxatives include:

  • Magnesium citrate (Citroma)
  • Magnesium hydroxide (Milk of Magnesia)
  • Polyethylene glycol (MiraLAX)

Osmotic laxatives work fast; oral forms may produce a bowel movement within 30 minutes.

Osmotic laxatives are generally considered safe, though it’s important to stay hydrated when taking them. 

They can be used frequently, but long-term use may decrease how effective they are. 

Some osmotic laxatives may cause stomach cramping, intestinal pain, or diarrhea.


Lubricant laxatives help make stool easier to pass by coating it. 

Mineral oil is a common lubricant laxative that typically produces a bowel movement within 6-8 hours.

Do not use lubricants long term, or the body can become dependent on their effects. 

Long-term use may also cause vitamin deficiencies, specifically with vitamins A, D, E, and K, which are absorbed in the large intestine.


Enemas and suppositories bypass the need to orally absorb since they are inserted directly into the rectum. 

They may work more quickly than oral options.

Enemas come with different active ingredients.

Some OTC options are:

  • Docusate (stool softener)
  • Bisacodyl (stimulant)
  • Sodium phosphate enema (osmotics)
  • Glycerin suppository (osmotics)
  • Mineral oil (lubricant)

Enemas and suppositories work quickly and may produce a bowel movement within minutes or up to an hour. 

Do not use an enema or suppository if you need to leave the house or be away from a bathroom.

They are not meant for long-term use.

Prescription Medicine for Constipation

If over-the-counter medications do not resolve constipation or it remains a chronic problem, a medical provider may suggest prescription medication. 

These are not laxatives and do not typically provide fast relief. 

Instead, they are meant for long-term use to help address chronic conditions.

Prescription medications for constipation are meant to be taken daily and should lead to regular bowel movements once they have been in the body for a few days or weeks.

The following prescription options treat constipation.


Linaclotide (Linzess) controls the amount of fluid that is in the digestive tract. 

It can also increase motility, which means that it helps stool move more quickly through the intestines.

Linaclotide treats constipation and irritable bowel syndrome with constipation (IBS-C).

Linzess is an oral capsule that has no generic available. 

It may cause side diarrhea, abdominal pain, bloating, and gas.


Plecanatide (Trulance) treats chronic constipation.

It regulates intestinal fluids to prevent stool from becoming too dry or hard. 

It also increases how quickly the bowels work to move contents through.

Trulance has no generic equivalent. 

Side effects include abdominal pain, bloating, gas, and diarrhea.


Lubiprostone (Amitiza) increases fluid in the gastrointestinal tract, making it easier to move stool through.

Lubiprostone can treat chronic constipation, IBS-C, and constipation caused by opioids. 

Side effects may include abdominal pain, nausea, or diarrhea.


Methylnaltrexone (Relistor) treats opioid-induced constipation. 

It blocks opioids from binding to receptors in the gut and causing constipation, but it does not decrease their ability to block pain signals in the brain.

Methylnaltrexone can be taken orally or given as an injection. 

It may cause side effects of nausea, abdominal pain, or diarrhea.


Naloxegol (Movantik) treats constipation caused by opioids. 

It blocks them from binding to gut receptors but does not prevent opioids from blocking pain signals in the brain.

Naloxegol is taken orally. 

It may cause abdominal pain, diarrhea, nausea, and other side effects.


Naldemedine (Symproic) is a prescription medication primarily used to treat constipation from opioid use of longer than four weeks. 

It blocks opioids’ ability to interfere with normal intestinal function but does not decrease their pain-relieving abilities.

Taken orally, naldemedine may have common side effects such as abdominal pain, nausea, diarrhea, and gastroenteritis.

Other Treatment Options

In addition to OTC and prescription treatments for constipation, other treatment options may improve long-term intestinal function.

Training pelvic muscles using biofeedback can help. 

A physical therapist utilizes devices to help train you to fully relax and tighten pelvic floor muscles. 

Learning how to fully relax can improve the ability to pass bowel movements without straining or pain.

Other methods to treat and prevent constipation include lifestyle changes such as:

  • Staying well hydrated
  • Eating high-fiber foods such as fruits, vegetables, and whole grains
  • Getting regular physical activity
  • Having bowel movements when you feel the urge
  • Avoiding overuse of laxatives

Concerned about constipation? Chat with a provider using K Health.

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When to See a Medical Provider

Over-the-counter laxatives can make it easy to address occasional constipation at home. 

But if you frequently have problems with bowel movements, check with a medical provider. 

Tell them if any of the following are true for you:

  • You go more than three days without a bowel movement
  • You are pregnant or breastfeeding
  • You have severe abdominal pain or cramping
  • There’s blood in your stool
  • Your bowel movements appear black and tarry
  • You have frequent dizziness, fatigue, or muscle weakness
  • You have unexplained weight loss of 10 pounds or more
  • You have been using laxatives but they are not working

Children or infants who are constipated should see a medical provider. 

Consult with their pediatrician before using laxatives.

Leaving constipation untreated can increase your risk for:

How K Health Can Help

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Frequently Asked Questions

Which is the best medicine for constipation?
Over-the-counter constipation options include laxatives like bisacodyl (Dulcolax), polyethylene glycol (Miralax), and senna (Ex-Lax, Senokot). These are effective and produce bowel movements within a few hours. Use laxatives as directed to avoid chronic constipation.
How can I treat constipation fast?
The fastest way to relieve constipation is to use a laxative suppository or enema. If you want an oral option, OTC medications like osmotics, stimulants, or lubricants are the fastest-working laxatives. These include products like Milk of Magnesia, Dulcolax, and mineral oil.
Is Dulcolax good for constipation?
Dulcolax is a type of stimulant laxative, which means that it prompts the intestines to empty more quickly. It typically works within 6-10 hours. Dulcolax is effective for providing constipation relief. It may also be used to clear the intestines prior to surgical procedures or colonoscopies.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

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Alicia Wooldridge, MD

Dr. Alicia Wooldridge is a board certified Family Medicine physician with over a decade of experience.