Chronic Constipation: A Stepwise, Evidence-Based Approach to Relief

The short answer#

To relieve constipation, start with more fiber (built up slowly toward the mid-20s to upper-30s of grams a day), enough fluid to go with it, and regular movement. If that is not enough, add a low-cost osmotic laxative such as polyethylene glycol, sold over the counter as Miralax. Stimulant laxatives like senna or bisacodyl work well as backup, and prescription drugs called secretagogues are options when the over-the-counter steps fall short. A sudden change in bowel habits, blood in the stool, unexplained weight loss, or anemia should send you to a clinician rather than to another laxative.

Key points#

• Constipation usually means fewer than three bowel movements a week, or stools that are hard, lumpy, painful, or feel incomplete. It is common, affecting roughly 16 of every 100 adults and about a third of adults over 60.
• First-line care is not a drug: more fiber (ideally soluble fiber such as psyllium), adequate fluids, physical activity, and a set toilet time after breakfast.
• Among laxatives, an osmotic agent (polyethylene glycol) has the strongest evidence and is the usual first medication. It outperforms lactulose head to head.
• Stimulant laxatives (senna, bisacodyl) are effective and reasonable as regular or backup use; long-standing fears of "damaging" the bowel are not well supported.
• Prescription drugs (linaclotide, plecanatide, and lubiprostone as secretagogues; prucalopride as a prokinetic) are for people who do not respond to over-the-counter measures, not a starting point.
• Alarm features (bleeding, weight loss, anemia, a new change after about age 45 to 50, a family history of colorectal cancer) change the plan and call for evaluation, often colonoscopy.

What counts as constipation, in plain terms?#

Most people picture constipation as simply not going often enough, but clinicians look at a wider set of clues. The US National Institute of Diabetes and Digestive and Kidney Diseases describes it as having fewer than three bowel movements a week, or stools that are hard, dry, or lumpy, difficult or painful to pass, or that leave a feeling of not being fully emptied. Any one of those can count, and normal patterns vary widely from person to person.

It is common, and it becomes more common with age. Roughly 16 of every 100 adults report constipation symptoms, rising to about 33 of every 100 adults aged 60 and older. Women, people who eat little fiber, and those on certain medications are more often affected.

"Chronic" means the problem has been around for a while. The research-standard Rome IV definition asks for symptoms present over the last three months, with onset at least six months earlier, and this is the picture this guide addresses. One important word in the guidelines is "idiopathic," meaning constipation with no secondary cause found. Before settling on that label, a clinician looks for culprits such as thyroid disease, diabetes, low potassium or high calcium, and medications, opioids in particular, which are a frequent and reversible driver.

How do you relieve constipation at home?#

The first steps are lifestyle changes, and they help a large share of people before any medication is needed.

Fiber, built up slowly. Fiber adds bulk and water to stool so it moves more easily. General targets land around 22 to 34 grams a day (roughly 25 grams for women and 38 for men), yet the average US adult gets only about 15 to 16 grams, close to half the goal. Add it gradually over a couple of weeks to limit gas and bloating, and drink enough fluid alongside it, because fiber without water can backfire. If you want the broader case for fiber beyond the bathroom, our companion piece on dietary fiber for metabolic and gut health walks through it.

Choose soluble fiber first. Not all fiber behaves the same for constipation. Soluble, gel-forming fiber such as psyllium has the better track record. In a 2011 systematic review summarized in a 2022 American Family Physician review, soluble gel-forming fiber such as psyllium improved global symptoms in 86.5 percent of people compared with 47.4 percent on placebo, and reduced straining (55.6 percent versus 28.6 percent), while the evidence for insoluble fiber was inconsistent. Wheat bran and other coarse insoluble fibers can worsen bloating in some people.

Move, and use the body's own timing. Regular physical activity supports normal bowel function. So does timing: the colon is most active after meals, so sitting on the toilet for a few unhurried minutes 15 to 45 minutes after breakfast takes advantage of that natural push and can retrain a sluggish routine.

If several weeks of these measures do not do the job, adding a laxative is the reasonable next step.

Which laxative is best: osmotic versus stimulant?#

This is the most common practical question, and the evidence gives a fairly clear order. The 2023 joint guideline from the American Gastroenterological Association and the American College of Gastroenterology reviewed the options and put the strongest support behind an osmotic laxative.

Osmotic laxatives pull water into the colon to soften stool and get things moving. Polyethylene glycol (PEG, or Miralax) is the preferred first choice: it earned a strong recommendation on moderate-certainty evidence and is the usual first drug to try. Head to head, PEG beats lactulose, another osmotic agent. A Cochrane review pooling 10 randomized trials with 868 participants found PEG produced more bowel movements per week, softer stool, and less need for extra products, which is why guidelines favor it over lactulose. The 2023 guideline also added magnesium oxide and the stimulant senna as evidence-based options, both on more limited, lower-certainty evidence.

Stimulant laxatives, such as senna and bisacodyl, prod the bowel wall to contract. They work reliably and act fairly quickly, which makes them useful either on a regular schedule or as backup when an osmotic agent alone is not enough. The old worry that routine stimulant use permanently harms or "wears out" the colon is not well supported by current evidence, though as-needed use is still a common pattern.

A rough guide to the over-the-counter shelf:

Stool softeners like docusate are widely sold but have modest evidence, so they are not the workhorse many assume. Cost, convenience, and how your body responds all reasonably factor into the choice, and it is fine to combine a daily osmotic agent with an occasional stimulant.

What about the newer prescription options?#

When fiber and over-the-counter laxatives have been given a fair trial and constipation persists, a clinician may turn to prescription drugs. Most work as secretagogues, meaning they increase the fluid the intestine secretes so stool passes more easily.

• Linaclotide (Linzess) and plecanatide (Trulance) activate a gut receptor (guanylate cyclase-C) that boosts intestinal fluid. Both carry strong recommendations in the 2023 guideline on moderate-certainty evidence.
• Prucalopride (Motegrity) is a prokinetic that speeds colonic transit through a serotonin (5-HT4) pathway, also strongly recommended.
• Lubiprostone (Amitiza) opens chloride channels to add fluid; it received a conditional (weaker) recommendation on lower-certainty evidence.

The consistent guideline message is sequencing: these are for people who do not respond to cheaper over-the-counter agents, not a first move. The most common side effect is diarrhea, and linaclotide and plecanatide should not be used in young children. Cost and insurance coverage genuinely matter here, since prescribing a drug a person cannot afford helps no one, so the pattern is to establish a need before reaching for them.

When is constipation a warning sign?#

Most constipation is a nuisance, not a danger. But a specific short list of features shifts the plan from self-care to evaluation, because they can signal colorectal cancer, inflammatory bowel disease, or a blockage. The 2022 American Family Physician review flags these alarm features:

• Blood in the stool or rectal bleeding
• Unintentional weight loss (about 10 pounds or more)
• Iron-deficiency anemia or a positive stool blood test
• A new change in bowel habits, especially starting after roughly age 45 to 50
• Narrowing of the stool caliber
• A family history of colorectal cancer or inflammatory bowel disease, or being overdue for colorectal cancer screening

Any of these deserves a clinician's assessment and often a colonoscopy rather than another round of laxatives. We cover this in more depth in our note on constipation with alarm features. Separately, if you have severe abdominal pain with vomiting and an inability to pass stool or gas, that can indicate a bowel obstruction and is an emergency worth same-day care. And when the harder question is whether ongoing symptoms reflect inflammation or a functional pattern, our explainer on how IBD and IBS are told apart may help frame the conversation. For related digestive topics, see our kidney, digestive, and blood health section.

The bottom line#

A stepwise plan handles the large majority of chronic constipation: fiber and fluids first, then a preferred osmotic laxative such as polyethylene glycol, then a stimulant as backup, and prescription secretagogues reserved for cases that do not respond. Layered on top is a simple safety check, the alarm features above, that tells you when the answer is a clinic visit instead of a pharmacy aisle.

Talk with your own clinician about your symptoms, other conditions, and medications before starting or changing treatment.