Constipation is a medical term that can refer to either a reduction in the number of bowel movements each week or pain or difficulty passing stools.

There are two main types of constipation: primary and secondary. Primary constipation is constipation that occurs without any clear cause. Secondary constipation is that which occurs as a result of lifestyle factors or an underlying illness.

In this article, we outline the different types of primary and secondary constipation, including their causes and treatments. We also list some of the risk factors for constipation and offer advice on when to see a doctor.

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Doctors sometimes refer to primary constipation as “functional” or “idiopathic” constipation. These terms acknowledge that the constipation is the primary medical problem rather than a symptom of another underlying medical issue.

Below, we outline the three different types of primary constipation.

Normal transit constipation

Normal transit constipation is a condition in which a person perceives themselves to be constipated, but the consistency of their stools is normal, and the stools move through the digestive tract at a regular pace.

People with normal transit constipation may report experiencing symptoms such as abdominal bloating and pain.

Slow transit constipation

People with slow transit constipation do not experience the normal stimulation of the bowels, called peristalsis, after eating. Therefore, food moves through the digestive tract more slowly than usual, and stools take longer to pass through the colon.

As stool sits in the intestines for longer, these individuals will have less frequent bowel movements.

Outlet constipation

Outlet constipation occurs as a result of damage to the pelvic floor muscles. These muscles support the bowel and bladder, as well as the uterus in females.

In outlet constipation, damage to the pelvic floor muscles or nerves makes it difficult for a person to pass stools. This damage can occur for various reasons, including pregnancy and childbirth.

Some possible symptoms of outlet constipation include:

Secondary constipation is constipation that occurs as a result of an underlying health issue or a side effect of medication use. The most common causes of secondary constipation include:

Less common causes of secondary constipation include:

The treatment options for constipation vary among the different types.

Primary constipation

The most effective treatment will depend on whether a person has normal or slow transit constipation or outlet constipation.

Normal and slow transit constipation

Normal and slow transit constipation often respond well to changes to everyday routines, such as:

  • increasing fiber intake by eating more fruits, vegetables, and whole grains
  • drinking more water
  • getting more exercise

In some cases, a doctor may recommend medications called laxatives. These work to increase bowel movements or loosen stools.

People with IBS may respond to certain diets, such as low gluten diets or low FODMAP diets.

Outlet constipation

A person with pelvic floor damage may require targeted physical therapy to help strengthen their pelvic floor muscles. People who have pelvic floor nerve damage may benefit from a type of behavioral therapy called biofeedback therapy.

In biofeedback therapy, a trained therapist inserts a probe into the anal sphincter. The therapist then gives visual or verbal feedback about how the person is using their pelvic floor muscles and anal sphincter during bowel movements. This information helps the person retrain the pelvic floor muscles to improve their coordination.

Secondary constipation

The treatment for secondary constipation begins with identifying and treating the cause. For example, uncontrolled diabetes increases the risk of nerve damage that can lead to constipation. In this case, a person would need to manage their diabetes to treat the constipation.

While dietary and exercise changes will not treat the underlying cause of secondary constipation, they can prevent constipation from worsening while doctors treat the primary cause. These changes may include:

  • increasing physical activity
  • eating more fiber
  • drinking more fluids

In some cases, a person with secondary constipation may need surgery to repair or remove a dysfunctional part of their colon.

The following factors can increase a person’s chances of experiencing constipation:

  • Not drinking enough fluids: Water helps soften stools, enabling them to pass through the digestive tract more easily. Not drinking enough can make stools hard and difficult to pass.
  • Lifestyle factors: The following lifestyle factors could cause or contribute to constipation:
    • lack of physical activity
    • a low fiber diet
    • delaying bowel movements
  • Natal sex: Females are more likely than males to develop constipation. They are also more likely to experience certain types of pelvic floor damage, such as those that people sustain during pregnancy or childbirth.
  • Pregnancy: The hormonal changes that occur during pregnancy can lead to slowed digestion and constipation.
  • Certain health conditions: The following chronic health conditions may cause constipation:
    • hypothyroidism
    • diabetes
    • Parkinson’s disease
  • Medication use: Some medications can slow digestion or affect nerve function, thereby increasing the risk of constipation. Examples include:
    • some pain medications
    • some blood pressure medications
    • some medications that doctors use to treat Parkinson’s disease
  • Use of laxatives and enemas: Prolonged use of these constipation treatments may make it more difficult to have a bowel movement without them.

Occasional constipation is not dangerous. If the constipation goes away following at-home treatment, there is no need to see a doctor.

However, a person should see a doctor if they experience any of the following:

Constipation can refer to painful and difficult bowel movements or a reduction in the normal number of bowel movements. There are two main types of constipation: primary, which has no known cause, and secondary, which has an underlying cause.

People can often reduce primary constipation by making changes to their daily routine. These include drinking plenty of fluids, eating more high fiber foods, and increasing physical activity.

Untreated constipation can lead to health issues, such as stomach pain, bloody stools, and hemorrhoids. Anyone who experiences severe or persistent constipation should see their doctor, especially if other symptoms accompany the constipation.