Chronic functional constipation is persistent constipation that doesn’t have a clearly identifiable underlying cause.

Constipation is often defined as passing fewer than three bowel movements per week. Your bowel movements may be dry, lumpy, or hard.

Chronic functional constipation is a common problem, especially among children and older adults. Doctors often consider constipation chronic if it lasts longer than 3 months.

Functional constipation is estimated to affect between 10% and 23% of infants, children, and adolescents at any given time. As many as 80% of people in nursing homes may have chronic constipation.

Let’s take a deeper look at functional constipation, including symptoms, causes, and treatment options.

The primary symptom of constipation is passing stool less than three times per week. You may also have:

  • hard, dry, or lumpy stools
  • difficulty passing a bowel movement
  • a feeling that you haven’t passed stool after having a bowel movement

Many factors can contribute to the development of functional constipation. A combination of the following factors may play a role:

  • low fiber intake
  • high caffeine intake
  • high alcohol intake
  • low fluid intake
  • psychological stress or anxiety
  • low levels of physical activity
  • toilet training issues
  • medication side effects
  • family history
  • pain when passing bowel movements
  • fever
  • dehydration

Chronic functional constipation is common in both children and adults. Here are some risk factors in both groups.

Pediatric chronic functional constipation

Functional constipation is very common in children. About 3% of childhood doctor visits are related to constipation.

Risk factors in children might include:

Chronic functional constipation in adults

As many as 24% of adults have chronic constipation, and it tends to become more common with age. Factors that may increase the risk of developing constipation include:

Doctors often diagnose functional constipation using the Rome IV criteria. This set of criteria defines functional constipation separately for children and adults.

Infants and children under 4

Infants must have at least two of the following for 1 month:

  • two or fewer bowel movements per week
  • history of excessive stool retention
  • history of painful or hard bowel movements
  • history large stools
  • presence of a large stool in rectum

The following criteria may also be used for toilet-trained children:

  • at least one episode of incontinence per week
  • history of large stools that may clog the toilet

Above age 4

Children above the age of 4 must not meet the criteria for irritable bowel syndrome (IBS) and must have two of the following once per week for at least 1 month:

  • two or fewer bowel movements per week
  • at least one episode of fecal incontinence
  • history of avoiding having a bowel movement purposefully
  • history of painful or hard bowel movements
  • presence of large stool in rectum
  • history of large stools that may clog the toilet
  • symptoms that can’t be explained fully by another medical condition


Adults must have two or more of the following for the past 3 months, with symptom onset at least 6 months before.

  • straining during more than 25% of bowel movements
  • lumpy or hard stools in more than 25% of bowel movements
  • sensation of incomplete bowel movement in more than 25% of cases
  • sensation of blockage in more than 25% of bowel movements
  • needing manual maneuvers like pressing on your abdomen in at least 25% of bowel movements
  • fewer than three bowel movements per week
  • rarely having loose stools without the use of laxatives
  • not meeting the criteria for IBS

Diet or lifestyle changes alone might be enough to treat functional constipation in some cases.

The first treatment for functional constipation usually involves removing the hard stool from the colon. Laxatives containing polyethylene glycol have become the usual first-line treatment. In the past, doctors frequently used:

  • edemas
  • suppositories
  • manual removal

Once the excess stool is cleared out, doctors may recommend medications to keep the stool soft. These medications may include:

  • osmotic laxatives such as polyethylene glycol
  • stool softeners such as mineral oil
  • stimulant laxatives such as bisacodyl

About half of children will recover without the need for laxatives after 6–12 months. About 10% still need to take laxatives, and 40% continue to have symptoms despite taking laxatives.

Making some changes to you or your child’s lifestyle habits may help prevent functional constipation. Some changes you can make include:

  • eating a high-fiber diet, ideally 22–34 grams per day for adults
  • drinking plenty of fluids
  • minimizing intake of highly processed foods and meat
  • becoming physically active
  • minimizing dairy if you’re intolerant

Functional constipation is when you have fewer than three bowel movements a week with no obvious underlying cause. Chronic constipation is often considered constipation that lasts longer than 3 months.

Doctors often recommend laxatives to treat functional constipation. Increasing your fiber intake and exercising regularly may also help reduce your symptoms.