Chronic Functional Constipation With No Specific Cause

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Functional constipation, also known as chronic idiopathic constipation, is diagnosed when a person is experiencing constipation symptoms, but no specific cause for the problem can be identified. Because the physical cause can be found to explain the symptoms, functional constipation is one of the functional gastrointestinal disorders (FGDs).


People who experience functional constipation report some or all of the following symptoms:

  • Three or fewer bowel movements per week
  • Hard, lumpy stools
  • The feeling of incomplete evacuation
  • A sensation of blockage or obstruction in the anus and/or rectum
  • Straining during bowel movements
  • Use of fingers to assist in passing stool (digital evacuation)
  • Loose stools are rare without the use of laxatives

According to the Rome III criteria for FGDs, constipation symptoms must be experienced in at least 25 percent of all bowel movements. Symptoms also need to be present at least two days a week, for at least three months over the past six months, in order for a diagnosis of functional constipation to be made.

Functional Constipation Versus IBS

A diagnosis of functional constipation requires that your symptoms do not meet the criteria for irritable bowel syndrome (IBS). Typically it is the absence of pain associated with bowel movements that result in the diagnosis of functional constipation as opposed to IBS. Although the two disorders have different diagnostic criteria, some researchers believe that there is not a clear-cut distinction between the two. Many doctors will offer a diagnosis of IBS, even if the strict criteria are not met, to anyone who is experiencing chronic bowel problems with no identifiable cause. Many patients report that their symptom picture changes from one disorder to the other and back again over time.

Functional Constipation in Children

The Rome IV diagnostic criteria for functional constipation in infant, toddlers, and children differ from those for adults:

  • Constipation is defined as two or fewer bowel movements per week.
  • At least one episode of soiling per week (in those who are toilet trained)
  • History of holding stool in
  • Painful, hard bowel movements
  • Impacted stool in the rectum
  • The experience of stools that are so large they may clog the toilet

Your child may also display irritability and a decreased appetite, but mood lifts and appetite increases once they are able to pass a large stool. As with functional constipation in adults, the diagnosis is only made in children who do not meet the criteria for IBS.

Chronic constipation is one of the top ten problems that bring children in to see their pediatrician. It is estimated that 90 to 95 percent of the time the problem is diagnosed as functional, with only a very small percentage of children having an identifiable problem to account for their constipation symptoms. The problem is most likely to show up between the ages of two and four and is typically related to the onset of toilet training.

A large percentage of children who have functional constipation also experience fecal incontinence, as loose stool leaks out around the hard mass. Approximately one-third of children with functional constipation will demonstrate behavioral difficulties related to their symptoms.


The treatment for functional constipation is different for adults and children. If you, or your child, are experiencing symptoms of chronic constipation, it is essential that you see a doctor for an appropriate diagnostic workup. If your doctor comes up with a diagnosis of constipation, they will work with you to develop a treatment plan.

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