Laxatives: Types, Side-Effects, Contraindications, Interactions, Precautions


Laxatives are a type of OTC medicine used to treat constipation. Over-the-counter (OTC) medicines are medicines that can buy without a prescription.


Different types of laxatives are:

A. Osmotic laxatives: An osmotic laxative helps the intestine to retain more fluid. They soften stools and also helps the bowel move them out. For Examples, polyethylene glycol and magnesium hydroxide solution (called milk of magnesia).
Side effect: Bloating, cramping, diarrhea, nausea, gas, and increased thirst etc.

B. Bulk-forming laxatives: They add “soluble” fiber to the stool. As a result, the stool absorbs more water and creates larger and softer stools. The softer and larger stools help to trigger the bowel to contract and move the stools out. They are the safest type of laxative. For examples, psyllium, polycarbophil, and methylcellulose. In the case of taking this laxative, patient should drink plenty of fluids.

Side effect: Bloating, gas, cramping or increased constipation if not taken with enough water.

C. Lubricant laxatives: They work by coating the surface of the stools to make them more slippery and helps the stools move out of the body more easily. Lubricants are simple and inexpensive. For example, Glycerin Suppositories.

Side effect: Discomfort etc. If you use lubricant laxatives correctly, they don’t have any side effects.

D. Stool softener: Stool softeners help to mix fluid into stools to soften them. As a result, stools easily pass out of the body. For example, docusate, also known as docusate salts or dioctyl sulfosuccinate.

Side effect: Electrolyte imbalance with prolonged use in case of children and people who have diabetes or kidney disease.

E. Stimulant laxatives: They are the harshest type of laxatives. They cause the bowel to squeeze or contract to move the stools out. Stimulant laxatives should not use for more than a few days. In the case of long-term use, the bowel forgets how to push the stool out on its own due to loss of its muscle tone. For examples, Bisacodyl and sennosides.

Side effect: Belching, cramping, diarrhea, nausea and urine discoloration.

Drug-drug Interactions

  • Laxatives can interact with blood thinners substances such as warfarin (Coumadin), some antibiotics, and certain heart and bone medications.
  • After taking antacids or drinking milk within one hour don’t take bisacodyl.
  • Mineral oil and castor oil sometimes use as laxatives, but they shouldn’t use often. Deficiency of vitamins A, D, E, and K occur due to the use of mineral oil. Castor oil (a stimulant laxative) can lead to chronic constipation because it can cause to lose bowel muscle tone. Also, Castor oil and Mineral oil interact with antibiotics such as tetracycline, blood-thinning medicines, and certain bone and heart medicines.


  • Use of Laxative can be dangerous if constipation is caused by a serious condition, such as appendicitis or bowel obstruction. Frequently use of laxatives for weeks or months can decrease colon’s ability to contract and worsen constipation.
  • If a patient has an allergy to any of the ingredients of the laxative, don’t take that laxative.
  • If a patient has a condition called phenylketonuria, he/she shouldn’t take a laxative that contains phenylalanine.


  • Without a doctor’s recommendation don’t give to children under age six
  • In the case of pregnant woman ask a doctor before using laxatives. Bulk-forming laxatives and stool softeners are safe to use during pregnancy, but stimulant laxatives may be harmful.
  • If a patient has recently given birth, consult your doctor before using. Although they’re usually safe to use during breastfeeding, some ingredients may pass into breast milk and cause diarrhea in nursing infants.
  • Contact a doctor immediately if anyone has bloody stools, severe cramps, pain, weakness, dizziness, unusual tiredness or rectal bleeding.
  • If you have an unexplained change in bowel patterns or constipation last longer than seven days despite laxative use, you should consult your doctor.
  • Don’t use laxatives for longer than one week unless doctor recommendation.
  • Phenolphthalein may increase chances of cancer. So, you should not use stimulant laxatives containing phenolphthalein.

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