Medications for Constipation Relief

Several types of medications and supplements are readily available and help provide effective relief from constipation. 

Depending on the type and mode of delivery, medications for constipation are available in the form of tablets, powders, wafers, liquids, and solid preparations for insertion into the rectum (suppository). 

Over-the-Counter Constipation Medications

Non-prescription constipation medications, called laxatives, help prevent or manage constipation after spine surgery. Laxatives are available at most grocery stores, convenience stores, and pharmacies.

Effective OTC options are described below.

Osmotic laxatives

These drugs enable the retention of water inside the cavity of the intestine, adding bulk to the stool and helping to soften it. ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.

Polyethylene glycol or PEG (Miralax), magnesium-based laxatives, such as Milk of Magnesia or magnesium citrate, and lactulose are examples of osmotic laxatives.

Magnesium-based compounds, such as magnesium citrate, are further classified as saline laxatives and act quickly, producing a bowel movement in 30 minutes to 3 hours. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

Osmotic laxatives, such as PEG, are poorly absorbed into the body and almost 100% of the drug is excreted, making them well tolerated with a lower risk of adverse effects. ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.

Stool softeners

Emollient laxatives help fluids mix with stool to make it soft and aid with a bowel movement. Stool softeners include docusate (Colace, Dialose, Surfak) and iron with docusate (Ferro-DSS).

Stool softeners usually take 1-3 days to take effect.

Stool softeners are best used as medications to prevent constipation and may not be effective if constipation has already occurred. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

Stimulant laxatives

These medicines act on the nerves that power the muscles of the intestine to stimulate bowel contractions and move stool out of the rectum. ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.

Stimulant laxatives take 6-12 hours to work ³ Laxatives. nhs.uk. Available from: https://www.nhs.uk/conditions/laxatives/. Accessed on 25 July 2023. and are categorized as follows: 

• Diphenylmethane derivatives (eg, bisacodyl [Dulcolax] and sodium picosulfate) ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.
• Plant-based anthraquinones (eg, senna [Senokot], aloe, and cascara) ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.

These drugs may possess irritant properties that cause diarrhea and abdominal pain in some individuals. ¹ Rao SSC, Brenner DM. Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review. Am J Gastroenterol. 2021 Jun 1;116(6):1156-1181. doi: 10.14309/ajg.0000000000001222. PMID: 33767108; PMCID: PMC8191753.

Bulk-forming laxatives

These drugs help increase the bulk or weight of the stool and also help soften it, stimulating a bowel movement. ³ Laxatives. nhs.uk. Available from: https://www.nhs.uk/conditions/laxatives/. Accessed on 25 July 2023.  Examples include psyllium (Metamucil), calcium polycarbophil (FiberCon), and methylcellulose fiber (Citrucel). 

This type of laxative usually takes 2-3 days to be effective. ³ Laxatives. nhs.uk. Available from: https://www.nhs.uk/conditions/laxatives/. Accessed on 25 July 2023.

Bulk-forming laxatives must be avoided in patients taking opioid medications after surgery. The action of opioid medications prevents the intestinal movements induced by this specific laxative, potentially worsening abdominal pain and contributing to bowel obstruction. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

Suppositories

A suppository is a small round, conical, or cylindrical-shaped structure that contains a medical preparation. Suppositories are inserted into the rectum and dissolve quickly to release the medication. These drugs act fast and stimulate the colon to contract and push the stool out.

Examples of suppositories include bisacodyl (Dulcolax) and glycerin (Fleet). 

Enemas

Enemas are injectable liquids that are administered in the rectum and upward into the colon. They help stimulate the colon to pass stools. 

Examples of liquids used in an enema include water, saline, or mineral oil (Fleet).

For all medications, including over-the-counter versions, it is important to read the directions carefully and/or consult a pharmacist or primary care provider if there are any questions.

Prescription Medications for Constipation

Prescription medications are recommended when OTC options are ineffective in easing the symptoms of constipation. 

Patients recovering from surgery, and especially those with opioid-induced constipation (when constipation occurs as a side effect of taking opioid pain medications), may need prescription-grade medications to aid in a bowel movement.

Prescription medications for constipation include:

Opiate agonists and antagonists

These drugs block the effects of opioid medications in the intestine that lead to constipation, while still allowing the pain-relieving effects of the drug to work on the body. Opiate agonists are not used in patients with peptic ulcer, colon cancer, or intestinal obstruction. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

See Opioid Medication Potential Risks and Complications

Methylnaltrexone (Relistor) is an example of this drug and may be taken as a tablet or an injection. 

Additionally, naloxegol (Movantik) blocks mu-opioid receptors in the bowel and can be used to treat opioid-related constipation.

Type-2 chloride channel activators

These drugs increase the secretion of fluids in the intestine and increase the tone, motility, and speed of muscle activity in the intestine – aiding in a bowel movement. They also help increase the overall frequency of bowel movements each week. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

Lubiprostone (Amitiza) is an example of a type-2 chloride channel activator. This drug may be used in patients with or without cancer. ² Sizar O, Genova R, Gupta M. Opioid-Induced Constipation. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493184/

Other prescription medications include naloxegol (Movantik) and naldemedine (Symproic). 

Vitamins and Supplements to Ease Constipation

It is surprising how effective many supplements are in stimulating regular bowel movements.  The supplements tend to have the added benefit of providing the body with essential vitamins and minerals that are healthy and necessary. 

For example, magnesium fosters regular bowel movements and has also been found to be deficient in 45% of adults in the US. ⁴ Zhang L, Du Z, Li Z, Yu F, Li L. Association of dietary magnesium intake with chronic constipation among US adults: Evidence from the National Health and Nutrition Examination Survey. Food Sci Nutr. 2021 Sep 29;9(12):6634-6641. doi: 10.1002/fsn3.2611. PMID: 34925793; PMCID: PMC8645769. ^{, 5} Workinger JL, Doyle RP, Bortz J. Challenges in the Diagnosis of Magnesium Status. Nutrients. 2018 Sep 1;10(9):1202. doi: 10.3390/nu10091202. PMID: 30200431; PMCID: PMC6163803.

Important vitamins and dietary supplements that help relieve constipation are:

Magnesium

Adding more magnesium to the diet enhances the absorption of water into the intestines, causing dilation of blood vessels and stimulation of the muscles, improving bowel movement. ⁶ Moradian ST, Ghiasi MS, Mohamadpour A, Siavash Y. Oral magnesium supplementation reduces the incidence of gastrointestinal complications following cardiac surgery: a randomized clinical trial. Magnesium Research. 2017;30(1):28-34. doi:10.1684/mrh.2017.0420

• Magnesium supplements are available in the form of tablets containing magnesium oxide as the active ingredient. 
• The exact dosage of magnesium varies for each individual and depends on the patient’s age and other medical conditions. 

In rare cases, prolonged or excessive intake of magnesium supplements or drugs containing magnesium (eg, laxatives and antacids) may cause hypermagnesemia. ⁷ Cascella M, Vaqar S. Hypermagnesemia. [Updated 2023 Jun 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549811/

Common symptoms of hypermagnesemia include weakness, fatigue, nausea, vomiting, and headache. This risk is typically higher in patients with impaired kidney function. ⁷ Cascella M, Vaqar S. Hypermagnesemia. [Updated 2023 Jun 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549811/

Kiwifruit extracts

Kiwifruits are rich in fiber, vitamins, and specific nutrients that help in ⁸ Eltorki M, Leong R, Ratcliffe EM. Kiwifruit and Kiwifruit Extracts for Treatment of Constipation: A Systematic Review and Meta-Analysis. Can J Gastroenterol Hepatol. 2022 Oct 6;2022:7596920. doi: 10.1155/2022/7596920. PMID: 36247043; PMCID: PMC9560827. :

• Improving intestinal movements 
• Digesting protein and emptying the stomach through the action of a special enzyme, actinidin
• Improving the gut’s microflora (bacteria)

A combination of the above processes helps in the propulsion of stool out of the intestines, preventing build-up and constipation. ⁸ Eltorki M, Leong R, Ratcliffe EM. Kiwifruit and Kiwifruit Extracts for Treatment of Constipation: A Systematic Review and Meta-Analysis. Can J Gastroenterol Hepatol. 2022 Oct 6;2022:7596920. doi: 10.1155/2022/7596920. PMID: 36247043; PMCID: PMC9560827.

Kiwifruit extracts are available as chewable capsules from freeze-dried kiwifruit. ⁸ Eltorki M, Leong R, Ratcliffe EM. Kiwifruit and Kiwifruit Extracts for Treatment of Constipation: A Systematic Review and Meta-Analysis. Can J Gastroenterol Hepatol. 2022 Oct 6;2022:7596920. doi: 10.1155/2022/7596920. PMID: 36247043; PMCID: PMC9560827.

Flaxseed oil

The oil, mucilage, soluble fiber, and insoluble fiber contained in flaxseeds may help ease constipation by lubricating the intestines and softening the stool. ⁹ Hanif Palla A, Gilani AH. Dual effectiveness of Flaxseed in constipation and diarrhea: Possible mechanism. Journal of Ethnopharmacology. 2015;169:60-68. doi:10.1016/j.jep.2015.03.064 ^{, 10} Bellini M, Tonarelli S, Barracca F, Rettura F, Pancetti A, Ceccarelli L, Ricchiuti A, Costa F, de Bortoli N, Marchi S, Rossi A. Chronic Constipation: Is a Nutritional Approach Reasonable? Nutrients. 2021 Sep 26;13(10):3386. doi: 10.3390/nu13103386. PMID: 34684388; PMCID: PMC8538724.

Flaxseeds can be added to cereals, baked goods, or smoothies. Flaxseed oil may also be taken as a dietary supplement, available in the form of capsules. 

Probiotics

Probiotics contain strains of live bacteria and yeast that are part of a healthy gastrointestinal system. They help improve gastrointestinal health and relieve constipation by ¹¹ Dimidi E, Christodoulides S, Fragkos KC, Scott SM, Whelan K. The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2014;100(4):1075-1084. doi:10.3945/ajcn.114.089151 :

• Modifying intestinal bacteria to foster a more natural and balanced environment 
• Altering intestinal function to improve bowel movement and shorten the time taken to propel stool 

Probiotics are available in the form of chewable gummies, tablets, sachets, and fortified foods such as yogurt, milk, and beverages. ¹¹ Dimidi E, Christodoulides S, Fragkos KC, Scott SM, Whelan K. The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2014;100(4):1075-1084. doi:10.3945/ajcn.114.089151

The above suggestions include a variety of ways patients can prevent or manage constipation following back surgery. However, if these actions do not produce results, or if discomfort or prolonged constipation is experienced, it is advisable to seek medical care. Usually, a primary care physician is best suited to treat constipation.