The lowdown on laxatives

In the grand scheme of things, constipation seems like a small problem—but deal with it for long enough, and it turns into a pretty big one. Cramping, feeling backed-up, and bloating affects your mood, appetite, and energy levels, especially when constipation lingers for longer than a few days. 

Enter over-the-counter (OTC) laxatives, which promise relief in exchange for minimal effort: pop a pill, wait six to 48 hours, and voila, you’re back to normal. The only problem? Laxatives aren’t as foolproof as they seem. There are many different kinds, making it hard to know which one you should take, when you need one, and how long it’s safe to use.

To help you with your constipation woes, use this guide to laxative use to bring you one step closer to relief.  

How do laxatives work?

Laxatives prompt you to have a bowel movement by stimulating your colon to produce stool or simply making it easier to pass whatever is already in there. They’re typically thought of as supplements and medicines, but some foods can serve as natural laxatives.

When most people experience occasional constipation, they reach for at-home remedies like drinking plenty of fluids and increasing fiber intake, says Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in California. Diet and lifestyle changes can often take care of the problem without resorting to medication.

If it doesn’t, this is usually the point when some kind of OTC laxative is introduced. Most consumers choose a type of laxative based on how long they have had symptoms, how severe the constipation is, and how quickly they want to see results.

Most laxatives take anywhere from six to 72 hours to take effect. Once bowel movements are produced, the amount of laxative in the body will naturally reduce, though the laxative effects could linger for a couple of days after the initial dose. 

Types of laxatives

Taking a laxative is only as easy as it sounds if you understand all the different types of laxatives and how each one works. Here’s a breakdown. 

Natural laxatives

Found in foods and beverages, natural laxatives contain certain elements—like enzymes or sugars—that can stimulate your colon to produce a bowel movement. Papayas, pears, kiwis, coffee, herbs like senna, oils such as castor oil, and fiber-rich grains like bran and barley can often get things moving or help you maintain a regular digestive pattern.

Oh, and don’t forget about prunes (yes, Grandpa was right!).

“Dried prunes have more sorbitol than fresh and can have laxative effects,” says Ashkan Farhadi, MD, a gastroenterologist at MemorialCare Orange Coast Medical Center in California. He recommends soaking up to five dried prunes in water overnight and eating them in the morning as a natural way to combat chronic constipation. 

Bulk-forming laxatives

If you aren’t getting enough laxative foods and beverages naturally in your diet, you might turn to a fiber supplement like Benefiber or Metamucil. These power players contain forms of fiber—such as psyllium husk or methylcellulose—that actually absorb water, changing the texture of your stool and prompting a natural contraction of your colon to push it out. They are typically considered safe for daily use. 

Emollient laxatives

Also known as stool softeners, emollient laxatives wetten and soften stool inside your colon so you don’t have to strain as much. They don’t force your colon to produce a bowel movement, only make existing stool easier to pass.

Although there’s no real evidence that taking a stool softener daily will harm you, it also won’t solve your underlying problem and the dosage might become ineffective over time.

Osmotic laxatives

These work by drawing water into the intestines, says Dr. Bedford, softening the stool and allowing you to pass movements more easily. These laxatives, such as Miralax, don’t cause any dependency and although they don’t work for everyone, they can be used daily if needed. 

There are a few kinds of osmotic laxatives utilizing different ingredients; lactulose laxatives are sugar-based, saline laxatives are salt-based, and polymer laxatives contain polyethylene glycol.

Stimulant laxatives

Like their name suggests, these laxatives stimulate your bowels to increase peristalsis, i.e., the contracting movements that cause stool to be passed. Containing ingredients such as bisacodyl or sennosides, they’re often taken as tablets (such as Ex-Lax), though some people drink them as herbal teas.

Lubricant laxatives

Lubricant products like mineral oil coat your stool, preventing the colon from losing water so you can pass stool more easily. People often drink mineral oil, or it may be inserted rectally for immediate results. Be sure to read the directions on the bottle.

When should you take a laxative?

There are many short-term scenarios which can cause constipation: travel, stress, illness, heat exposure, low hydration, pregnancy, dietary changes, and low levels of exercise or activity can all trigger a case of constipation. A one-time dose of an OTC laxative can clear away constipation, regulate your bowels, relieve bloating, and set you back on track again.

There are also long-term causes of constipation, with sufferers typically falling into three categories: the elderly, people on certain medications (like narcotics and certain antidepressants), and people with certain health conditions (like irritable bowel syndrome or diabetes).

It’s okay to use a laxative occasionally to address a short-term reason for constipation, but using a laxative long-term (or to address a chronic issue like another medication’s side effect) isn’t the best idea. Though they’re sold as OTC drugs, many laxatives can lead to side effects and dependency. They also don’t address your constipation at its source—they’re basically a bowel movement band-aid.

“People may become dependent on them or misuse them, and by the time they get to the physician, they’ve missed the original etymology,” says Dr. Bedford, who explains that constipation can be an early warning sign of a larger problem in some cases.

Long-term use is typically not indicated for any laxatives except Miralax and fiber supplements like Benefiber, according to Dr. Bedford. Unfortunately, most people follow a specific strategy: they try to treat their constipation with at-home remedies, then when those don’t work, they move onto stool softeners and then, typically, an osmotic or stimulant laxative.

By that point, however, the constipation should have been addressed by a physician.

“If a bulking agent doesn’t work and you move onto a softener and that doesn’t work, you really need to call your doctor,” says Bedford, who advises against graduating up to more serious forms of laxatives once these other measures fail.

Side effects of long-term use 

Water loss from laxatives may cause temporary weight loss, but do laxatives help you lose weight? Laxatives are neither an effective method for burning body fat nor a safe way to lose weight. People with binge eating disorders often turn to laxative abuse to lose weight, but this type of misuse can cause serious side effects and complications on your digestive health.

In the short-term, overusing laxatives can cause dehydration and electrolyte imbalances, says Dr. Bedford, disrupting your natural levels of nutrients like calcium, potassium, and magnesium. If laxative use persists, it can lead to kidney disease and heart disease.

Another common side effect is something known as cathartic colon or colonic inertia. “People who have chronic constipation and use laxatives daily can have a condition where the colon is dilated and lazy,” says Dr. Farhadi.

When this happens, your colonic muscles are no longer able to produce peristalsis or effectively move waste through your intestines on their own, having become too accustomed to the laxatives doing all the work for them. Dr. Farhadi says this is most commonly caused by overuse of stimulant laxatives.

Thankfully, the condition can be treated; the effects on the colon aren’t usually permanent as long as the use of stimulant laxatives is discontinued.

“When patients accept and understand [the relationship between stimulant laxatives and cathartic colon], and switch to an osmotic laxative like Miralax, the problems can usually be reversed within one year,” Dr. Farhadi explains.

Best laxatives 

The laxative that is best for you depends on your unique situation. But, if you’ve tried treating your constipation with natural laxatives to no avail, you may want to consider one of the following OTC laxatives.

 The bottom line 

If you’ve recently traveled, changed your diet, endured a stressful event, or simply had your normal routine disrupted, short-term use of a mild laxative such as Miralax or Colace can be helpful in getting your digestive system back on track.

But if you are noticing a recurrent pattern of constipation or reaching for more serious laxatives (like stimulant or lubricant varieties) on a regular basis, it’s time to head to your healthcare provider for an exam. Remember, laxatives don’t resolve the root cause of your constipation—finding out what’s behind your chronic constipation is often the necessary next step.