Safely Using Laxatives for Constipation

Medically Reviewed by Gabriela Pichardo, MD on May 11, 2022
4 min read

Tired of being constipated and think you might need a laxative? Millions of Americans suffer with symptoms of constipation:

Laxatives contain chemicals that help increase stool motility, bulk, and frequency -- thus relieving temporary constipation. But when misused or overused, they can cause problems, including chronic constipation. A healthy diet filled with fresh fruits, vegetables, and whole-grain products; regular exercise; and drinking the equivalent of at least eight 8oz cups of water daily can help prevent constipation in most people. The fluids can be not just water, but teas, soup and other forms of liquids. 

Still, 85% of doctor visits for constipation result in a prescription for a laxative. So it's important to understand how laxatives work and how to use them safely.

There are different types of laxatives that come in pills, capsules, and liquids; suppositories; and enemas. Each type of laxative has specific benefits and possible side effects. Though using a suppository or enema in the rectum is not as convenient (or pleasant) as swallowing a pill, these manually inserted (or squirted) laxatives often work much faster to relieve symptoms.

Fiber is the laxative most doctors recommend for normal and slow-transit constipation. Abdominal cramping, bloating, or gas can occur when abruptly increasing or changing your dietary fiber intake. Fiber is naturally available in fruits, vegetables, and whole grains (especially wheat bran). Fiber is also available over the counter in calcium polycarbophil (Equalactin, Fibercon), methylcellulose fiber (Citrucel), psyllium (Fiber-Lax. KonsylMetamucil), and wheat dextrin (Benefiber).   

Fiber works by increasing the water content and bulk of the stool, which helps to move it quickly through the colon. When taking fiber supplements, it's essential to drink enough water to minimize the possibility of flatulence and a possible obstruction.

People who increase their fiber may abruptly suffer abdominal cramping, bloating, or gas. Gradually increase fiber intake. Also, fiber can reduce your body's absorption of some drugs, so always take your medications at least one hour before -- or two hours after -- consuming fiber.

As the name implies, lubricant laxatives make stools slippery. The mineral oil within these products adds a slick layer to the intestine's walls and stops the stool from drying out. Though highly effective, lubricant laxatives are best used as a short-term cure for constipation. Over a longer period, mineral oil can absorb fat-soluble vitamins from the intestine, and decrease certain prescription drugs from being fully absorbed into the body. Do not take mineral oil at the same time as other medications or supplements.

Commonly known as "stool softeners," emollient laxatives such as Colace (or generic Colace) contain docusate, a surfactant that helps to "wet" and soften the stool. Although it might take a week or longer for emollient laxatives to be effective, they are frequently used by those who are recovering from surgery, women who have just given birth, or individuals with hemorrhoids.

"The wetter the better," is the osmotic laxative's mission. These products include Fleet Phospho-Soda, lucatose (Kristalose), magnesium hydroxide (Milk of Magnesia or MOM), lactitol (Pizensy), and polyethylene glycol (Miralax) -- all hydrating agents that draw fluids into the intestine from the surrounding tissues. More water in the intestine results in softer stools that are easier to pass. It's imperative to drink a lot of water with osmotic and hyperosmolar laxatives, not only for the laxative to be effective, but to decrease the possibility of gas and cramps.

Guanylate cyckase-C agonist laxatives change stool consistency by increasing the amount of water into the GI lumen and increasing gastrointestinal movement. Plecanatide (Trulance) is a prescription tablet for those suffering from chronic idiopathic constipation and irritable bowel syndrome with constipation. It’s not recommended for patients younger than six. While effective in promoting regular bowel function, it carries the risk of diarrhea and pediatric patients could develop severe dehydration.

Linaclotide (Linzess) and lubiprostone (Amitiza) work by drawing water into your intestines and speeding up the movement of stool. Amitiza is only approved for women.

If you're completely miserable and need almost instantaneous relief from constipation, the stimulant laxatives will do the job. This type of laxative works by stimulating the lining of the intestine, thereby accelerating the stool's journey through the colon. Stimulant laxatives also increase a stool's hydration. Some popular brands include bisacodyl (Correctol, DulcolaxFeen-a-Mint), and sennosides (Ex-LaxSenokot). Prunes (dried plums) are also an effective colonic stimulant and taste good, too. Note: Don't use stimulant laxatives daily or regularly. This type of laxative may weaken the body's natural ability to defecate and cause laxative dependency. One more caveat: the stimulant laxatives may cause cramping and diarrhea.

When using a laxative to cure occasional constipation, remember these tips:

  • If you need to use laxatives to be "regular," use fiber first.
  • Drink fluids and stay well hydrated when using laxatives. Avoid regular use of stimulant laxatives. Some can limit your body's ability to absorb vitamin D and calcium.
  • If your problem with constipation continues, see your doctor. Constipation may be a warning sign of a more serious problem such as colon cancer, diabetes, or hypothyroidism, among others. Your doctor can evaluate your medical history, do a physical exam and lab tests, and determine the exact cause and solution for constipation.