Constipation Treatments and Medications

Almost everyone has found themselves constipated or straining to pass stools. However, constipation is usually a temporary aggravation rather than a medical concern. When it persists for weeks to months, a condition called “chronic constipation,” something must be done about it.

Most people think constipation is having fewer than “normal” bowel movements, having trouble with bowel movements, straining to go, or having hard or smaller-than-normal-sized stools.

The causes of constipation may include lifestyle, behavior, psychology, diet, medications, anatomy, obstruction, muscle physiology, thyroid problems, irritable bowel syndrome, and illness. Constipation is also fairly common in small children and pregnant women, and functional constipation may occur due to certain debilitating circumstances such as a spinal cord injury. Because there are so many ways to get it, chronic constipation can affect anyone of any age or background. Still, chronic constipation is more common among women, those of lower socioeconomic status, the very young, older adults, the sedentary, and people who live in cold or rural climates.

All these symptoms can be grouped under constipation. They are usually not a medical concern unless they persist over time (chronic constipation) or are accompanied by “alarm” symptoms such as bloody stools. The best guess is that 16% of Americans have experienced chronic constipation at least once.

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The evaluation will begin with a thorough history, physical examination, and possibly a rectal examination, depending on the symptoms reported. Be prepared to answer the following questions on your first visit to a primary care physician:

If the initial fiber laxatives and lifestyle modifications don’t resolve the symptoms, more tests may be needed depending on the symptoms and history:

Stimulant laxatives include diphenylmethane derivatives such as bisacodyl (Dulcolax or Correctol) and sodium picosulfate, bile salts, and natural anthraquinones, such as sennosides from senna, emodin from aloe or buckthorn, and rhein from rhubarb root.

Additionally, self-administered enemas can be used to evacuate the bowels. Tap water is sufficient for most minor cases, but an oil-retention enema is required for hard stools or impaction.

Best constipation medications

Many of the standard dosages above are from the U.S. Food and Drug Administration (FDA) and the National Institutes of Health (NIH). Dosage is determined by your doctor based on your medical condition, response to treatment, age, and weight. Other possible side effects exist. This is not a complete list.

With those points aside, and in light of no studies confirming the optimal stepwise approach to laxative therapy, the best available recommendations include initiation of a bulk-forming laxative, then an osmotic laxative and followed by a stimulant laxative, if needed. The benefit is that these medications are often available over-the-counter, so access in a time of need is high. 

Bulk-forming laxatives can be used for both treatment and prevention of constipation and are available in many dosage forms–powders, wafers, capsules, and chewable tablets. They generally have an onset of action of 12 to 72 hours but often will be ineffective in aiding constipation due to slow transit, pelvic floor dysfunction, or due to medications. Because they must be taken with a minimum of 250 mL of water or juice to prevent fecal impaction and esophageal obstruction, these are not the best option in patients with any sort of dysphagia or esophageal strictures.

Osmotic laxatives are also an option for the prevention of constipation. Considerations for selecting one of these options is the onset of action: PEG has an onset of 2 to 3 days, while lactulose has an onset of action of 1 to 2 days, and glycerin suppositories work in less than 1 hour. PEG and lactulose are not absorbed and do not contain electrolytes, so are good options for patients with reduced kidney function, cardiac issues, or diabetes. Magnesium-containing products come with a risk of causing electrolyte imbalances and should be avoided in individuals with cardiac or renal dysfunction. 

Stimulant laxatives provide quick relief–within 6 to 12 hours. These are effective for prevention and treatment of constipation, and can offer benefit in slow transit constipation and neurogenic constipation. 

Agents with unique mechanisms of action, like prucalopride and linaclotide, have only been studied for treatment of refractory constipation, and should be implemented only after failure of the prior categories of laxatives. These prescription medications were studied in comparison to placebo, so it is difficult to determine if they fit in addition to these other options or instead of them. These medications are also only available by prescription, and may not be covered by insurance–or are priced on a higher tier co-pay. 

It is important to appropriately seek medical advice when dealing with constipation. Complications of constipation can include the development of hemorrhoids, which are swollen veins in the rectum due to straining, and anal fissures if hard stool tears the skin around the anus. Both of these complications can result in bleeding in and from the rectum. In children, constipation can also contribute to bladder control problems. Additional complications of chronic constipation in both children and adults include rectal prolapse, which is when a small piece of intestinal lining is pushed out of the anus, or fecal impaction in which hard, dry stool remains in the rectum causing other stool to back up in the colon. Inadequately managed chronic constipation can also result in loss of sensory and motor function.