A doctor is presenting medicine for constipation in the form of pills and tablets.

The best medicine for constipation examples include:

  • Emollient laxatives
  • Stimulant laxatives
  • Volume laxatives
  • Osmotic laxatives
  • Rectal suppositories
  • Pancreatic enzymes stimulants
  • Hepatic bile secretion stimulants
  • Lactulose
  • Plecanatide
  • Polyethylene Glycol
  • Prucalopride
  • Linaclotide
  • Lubiprostone.

O-T-C laxatives help episodic constipation and are easy to get. Prescription laxatives have better action and need the approval of your doctor.

Rectal suppositories are effective and work in the rectum area. Pancreatic enzyme stimulants and bile secretion stimulants help digestion.

Every type of medicine helps constipation and digestion.

Follow the rest of the guide and learn more about each type of medicine.


Emollient laxatives or stool softeners:

  • Require moisture to soften the stool.
  • They pull the water from the intestines.
  • Facilitate strain-free bowel movements.

They come in the form of tables or pills. Patients administrate them orally.

The best examples of stool softeners include Docusate Sodium, Surfak, and Docusate Calcium.

Docusate Sodium stimulates sodium and water secretion towards the intestines, producing lubrication and soaking of the bowl.

This type of medicine for constipation does not pose risks.

Emollient laxatives are less effective if there isn`t enough daily water intake.

Experts recommend using this type of laxative for the short term only.

A side effect can appear if you use them for a long time.

Electrolyte imbalance can appear after using these laxatives for a long time.

According to a medical study about pregnancy and constipation treatment published by the U.S. National Library of Medicine:

“Emollient laxatives belong to a group of anionic surfactants that allow water to enter the stool more readily.”
“The most frequently used are the docusate salts, sodium docusate, and calcium docusate, although there are other forms also available.”


Stimulant laxatives:

  • Trigger intestinal muscle contractions.
  • Squeeze the intestines to evacuate the stool.

Stimulant laxatives facilitate peristalsis stimulation.

They come in the form of small pills with oral administration.

This medicine for constipation is helpful for short-term treatments, especially for episodic constipation (that occurs occasionally).

Routine use of these contact laxatives is not suitable for anyone.

They induce the accentuation of peristalsis by stimulating the nerve endings in the mucous membrane of the colon.

The most popular stimulant laxatives are Senna, Bisacodyl (Dulcolax, Ducodyl, Correctol), Sennosides (Senekot, Senexon)

Stimulant laxatives contain polyphenolic and diaphenylmethane compounds like Bisacodyl.

They also contain anthranoid derivates like Senna.

The abusive use of stimulant laxatives reduces the tonus of the large intestine muscles and causes addiction.

This thing requires permanent administration to maintain the peristalsis process.

Stimulant laxatives have side effects such as diarrhea, nausea, belching, and intestinal cramps.

According to an updated systematic review of o-t-c therapies efficiency and safety published by The American Journal of Gastroenterology:

“Stimulant laxatives can be subdivided into two categories: diphenylmethane derivatives (e.g., bisacodyl and sodium picosulfate) and plant-based anthraquinones (e.g., senna, aloe, and cascara).”
“All act locally at the nerve plexus of smooth muscle in the intestine to stimulate colonic motility.”


Volume laxatives or oral bulk formers:

  • Expand the fecal matter.
  • Absorb water to form soft stool
  • Trigger intestinal muscle contractions.

They come in the form of tablets or pills with oral administration.

The best examples include Benefiber, FiberCon, Metamucil, Citrucel, and Perdiem.

These examples contain metochel or psyllium. Psyllium is an insoluble fiber that can fix a large quantity of water.

Volume laxatives are similar to foods based on wheat bran and psyllium.

Increased fecal bowl stimulates defecation reflexes.

Volume laxatives increase the number of ejections and have few side effects.

Some side effects can include gas, bloating, cramps, and dehydration.

Volume laxatives require water intake in large quantities.

Also, all experts refer to oral bulk forms as fiber supplements.

These laxatives take from 1-2 days to work.

According to a medical review called Laxative Use in the Community: A Literature Review:

“The popularity of laxatives chosen by adults to manage chronic or any constipation varied by country and/or region.”
“In North America, fiber/bulk-forming laxatives such as ispaghula were the most popular; stool softeners such as docusate were popular, and prescription products featured prominently in US studies.”


Osmotic laxatives facilitate:

  • Intestinal water diffusion.
  • Softening the stool.

They come in the form of small pills with oral administration.

The most popular osmotic laxatives are Magnesium Hydroxide, Magnesium Citrate, Philips’ Milk of Magnesia, Polyethylene Glycol, and Lactitol.

Products such as sodium phosphate, non-absorbable Magnesium, or non-absorbable disaccharides (Sorbitol and Lactulose) have a rapid effect.

They keep liquids in the intestinal lumen, pushing in the fluid flow from the blood vessels and the nearby tissues.

They create aqueous fecal matter.

Medical experts recommend to increase the daily intake of fluids when using this type of medicine for constipation.

People who suffer renal affections, high blood pressure, or are undergoing a non-salted regime should avoid using this type of laxatives.

These types of laxatives can cause nausea and diarrhea.

If you suffer from kidney failure or disease, visit a doctor first.

According to a medical guide called Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid published by the U.S. NCBI:

“Magnesium citrate is in a class of medications called osmotic laxatives. These medications work by causing watery diarrhea so that the stool can be emptied from the colon.”


The role of a rectal suppository is to trigger intestinal muscle contractions.

These contractions take place in an unordered rhythm,

The action of the suppository takes place in the rectum area.

The typical examples of rectal suppositories are Bisacodyl (Dulcolax), Glycerin, and Pedia-Lax).

Other types of suppositories soften the stool.

Possible side effects of rectal suppositories can include diarrhea, intestinal cramps, and rectal irritation.

Talk to your doctor before considering rectal suppositories to deal with constipation.

According to a medical overview of Constipation and Defecation Problems Overview published by The American College of Gastroenterology:

“Stimulant laxatives generally cause a bowel movement in six to eight hours. Some are available as suppositories. When taken as suppositories, these laxatives often work in 15 to 60 minutes.”


The main pancreatic enzymes that form pancreatin are:

  • Lipase
  • Amylase
  • Protease.

These digestive stimulating enzymes come in the form of tablets with oral administration.

A pancreatic enzyme stimulant tablet is an effective medicine for constipation because it has an immediate effect.

Pancreatic enzymes are helpful for people whose pancreas cannot produce sufficient enzymes anymore.

They are also helpful for digestion.

Tablets with pancreatic enzymes help the decomposition process of the nutrients to have proper absorption.

Lipase decomposes fats.

Amylase decomposes carbohydrates such as sugary foods, flour, starch, fructose, and glucose.

Protease determines the decomposition of the proteins, ensuring proper digestion and the optimal absorption of nutrients.

Digestive stimulating tablets are helpful when suffering from digestive disorders due to the lack of sufficient pancreatic enzyme secretion of various causes.

Insufficient exocrine pancreatitis is one of the most common examples.

When dealing with severe or episodic constipation, the standard dosage for adults is 1-2 tablets three times a day.

The administration should be during meals.

According to a medical guide about Amylase published by the U.S. National Library of Medicine:

“Amylase is an enzyme or special protein that helps you digest carbohydrates. Most of the Amylase in your body is made by your pancreas and salivary glands.”


This type of medicine for constipation comes in the form of tablets with oral administration.

The standard dosage for adults is 1-3 tablets taken 2-3 times a day.

The typical duration of treatment with stimulants in the form of tablets is 2-3 weeks.

The role of the bile is to intervene during the digestion and absorption processes of fats indirectly.

The chemical process takes place like this:

  • The bile emulsifies the fats.
  • After that, the bile activates the pancreatic lipase.

The pancreas secretes the lipase that has potent lipolytic action.

The chemical process absorbs fat-soluble vitamins such as A, D, E, and K.

Cholesterol and iron are also absorbed.

The bile favorizes intestinal peristalsis (which can have a laxative effect). And it neutralizes the acidity of the gastric juice when it reaches the intestine.

The liver continuously secretes bile. The digestive process stages facilitate the elimination of the bile.

Many causes influence its slow secretion.

According to a medical guide about Medication for IBS published by The International Foundation for Gastrointestinal Disorders:

“Sometimes, bile acids are not reabsorbed properly, leading to bile acid malabsorption.”
“Too much bile acid in the colon can result in watery stool, urgency, and fecal incontinence. This thing is why bile acid malabsorption is sometimes called bile acid diarrhea.”


Lactulose is an osmotic laxative that softens the stool by drawing water into the bowel.

It is a prescription-only laxative.

This laxative is more helpful than most O-T-C laxatives.

Lactulose is a non-absorbable sugar.

The purpose of Lactulose is to treat constipation and hepatic encephalopathy.

It comes in the form of tables with oral administration.

Also, it comes in the form of oral or rectal administration for hepatic encephalopathy.

The effect of this laxative starts from 8-12 hours.

The effect may take up to two days to help with constipation.

Lactulose benefits every patient in the long-term treatment.

This laxative has a few side effects: diarrhea, intestinal cramps, gas, and stomach irritation.

The most known types in the Lactulose laxatives category include Kristalose, Enulose, Cephulax, Duphalax, and Constulose.

Medical experts from Front Endocrinol (Lausanne) state that:

“The non-absorbable disaccharide lactulose is mostly used in the treatment of various gastrointestinal disorders such as chronic constipation and hepatic encephalopathy.”
“The mechanism of action of lactulose remains unclear, but it elicits more than osmotic laxative effects.”


Plecanatide or Trulance is a medicine for constipation that softens the stool.

The laxative draws water into the gastrointestinal tract.

This process makes stool evacuation feel natural.

The entire chemical mechanism of action is incredibly complex.

The mechanism of action is similar to osmotic laxatives but with different chemical components.

The purpose of this medication is to treat idiopathic constipation and irritable bowel syndrome with constipation.

Plecanatide is an agonist of guanylate cyclase-C.

This laxative increases intestinal transit and fluid through a buildup of Cyclic guanosine monophosphate.

Plecanatide or Trulance comes in the form of tablets with oral administration.

The recommended dosage of this laxative is 3 milligrams once a day.

The food does not affect the oral administration of the plecanatide tablets.

Diarrhea can be a side effect, and experts do not recommend this medication for persons between the age of 6-18.

Medical experts from the U.S. National Library of Medicine state that:

“No one drug will work for everyone. Some medicines are prescribed specifically for IBS with diarrhea (IBS-D) or IBS with constipation (IBS-C).”
“Medicines your provider may have you try include Laxatives, such as lubiprostone, linaclotide, plecanatide, bisacodyl, and other ones bought without a prescription for IBS-C.”


Polyethylene Glycol of PEG is the basis of numerous laxatives such as MiraLax, RestoLax, etc.

The chemical mechanism of PEG facilitates whole-bowel irrigation.

Adding electrolytes to the chemical mechanism facilitates bowel preparation before colonoscopy or surgery.

Macrogol is the standard name for using Polyethylene Glycol as a laxative.

The number that follows this name represents the average molecular weight (macrogol 3350, macrogol 600, etc.).

Talk to your doctor before considering polyethylene glycol as a medicine for constipation.

Polyethylene Glycol comes in the form of powder.

The powder mixes with water to form a laxative drink.

The most common side effects can be bloating, diarrhea, nausea, and intestinal cramps.

Any other negative symptoms are a warning signal to address a doctor.

According to a randomized clinical study called Comparative efficacy and safety of lactulose plus paraffin vs polyethylene glycol in functional constipation:

“Lactulose plus paraffin may be used interchangeably with polyethylene glycol for the pharmacological treatment of functional constipation.”


Prucalopride (Motegrity) improves intestinal motility and normalizes bowel movements.

It comes in the form of tables with oral administration.

This medication acts as a selective and high-affinity receptor agonist.

The EU, Canada, and The United States officially approved this medication for medical use in the past ten years.

The chemical mechanism of action stimulates colonic mass movements.

This process facilitates the main propulsive for fecal matter evacuation.

The entire chemical process is complex and includes different chemical components and receptors.

The most common side effects are headache, abdominal pain, diarrhea, and nausea.

These symptoms appear at the beginning of the treatment. They disappear within a few days.

Reach out to your doctor if the symptoms continue to develop during the oral administration of this laxative.

According to the official medical guide for treating constipation published by the U.S. National Institute of Digestive Diseases:

“Your doctor may prescribe one of the following medicines for constipation: prucalopride — which is a medicine that helps your colon move stool if you have long-lasting constipation without a known cause.”


Linaclotide is a drug that treats irritable bowel syndrome with constipation and chronic constipation.

It is a prescription-only drug and an oligo-peptide agonist of guanylate cyclase 2C.

Decide with your doctor if you really need this type of medicine.

After oral administration, this drug remains in the Gastrointestinal Tract for a while.

The chemical process of this drug is complex. It takes chemical knowledge to understand it.

his laxative works by increasing the intestinal fluid to accelerate the transit.

This drug is similar to an osmotic laxative.

Several brands sell this drug under the name of Linzess and Constella.

The purpose of this medicine is to treat irritable bowel syndrome with constipation.

The best part is that it treats constipation with no known causes.

Side effects include dehydration, low potassium, nausea, vomiting, fecal incontinence, and urgent need to evacuate the stool.

According to a randomized, placebo-controlled trial about Linaclodite published by the U.S. National Center for Biotechnology Information:

“Linaclotide is a guanylate cyclase‐C (GC‐C) agonist and a 14‐amino‐acid polypeptide minimally absorbed in the gastrointestinal tract.”
“Linaclotide binds to the GC‐C receptors of the intestinal mucosa, resulting in an increased production of cyclic guanosine monophosphate (cGMP) followed by a greater fluid secretion into the intestine and eventually increased gastrointestinal motility and alleviation of constipation. ”


Lubiprostone (Amitiza) is the perfect medicine for constipation for managing chronic idiopathic constipation.

It is also perfect for treating irritable bowel syndrome-associated constipation in women and opioid-induced constipation.

This medicine is prescription-only, so you should discuss it with your doctor first.

It is a more potent medicine than most O-T-C laxatives.

It comes in the form of liquid-filled capsules. It is only available with a doctor’s prescription.

The chemical process that takes place inside the intestines is complex.

This pill softens the stool by pulling water into it.

It acts similar to an osmotic laxative.

This process makes the stool evacuate with ease.

Adverse side effects include nausea, diarrhea, headache, abdominal distension, abdominal pain, flatulence, sinusitis, fecal incontinence, and vomiting.

Medical experts from The International Foundation for Gastrointestinal Disorders state that:

“Lubiprostone (Amitiza) is a prescription drug used to relieve stomach pain, bloating, and straining and produce softer and more frequent bowel movements in men and women who have chronic idiopathic (functional) constipation.”
“It works by increasing the amount of fluid that flows into the bowel. And it allows the stool to pass with ease.”

Last medically reviewed on 20.03.2024


1. Considerations for laxatives in terms of their interactions with other drugs. Gabrio Bassotti, Edda Battaglia.

2. European Medicines Agency. Guideline on the evaluation of medicinal products for the treatment of irritable bowel syndrome.

3. Pilot study on the effect of linaclotide in patients with chronic constipation. Jeffrey M Johnston, Caroline B Kurtz, Douglas A Drossman, Anthony J Lembo, Brenda I Jeglinski, James E MacDougall, Mark G Currie.

4. The relationship between irritable bowel syndrome and psychiatric disorders: from molecular changes to clinical manifestations. Mihaela Fadgyas-Stanculete, Ana-Maria Buga, Aurel Popa-Wagner, Dan L Dumitrascu.

5. Healthcare professionals’ experiences of assessing, treating and preventing constipation among older patients during hospitalization: an interview study. J Multidiscip Healthc. Lundberg V, Boström A-M, Gottberg K, Konradsen H.



My name is Sebastian D., and I am the senior editor of With the help of my mentor, Dr. Horia Marculescu, I decided to create a practical guide to constipation relief.. read more

Copyright © 2017-2024. All rights reserved. ConstipationGUIDE does not provide medical advice, diagnosis or treatment.