Constipation: Causes

What causes constipation?

Normally, the colon absorbs excessive water from food during digestion. When food moves too slowly, the colon absorbs too much water, resulting in hard, dry stool and constipation.

In young children, constipation can result from being afraid or unwilling to use the restroom, or delaying a bowel movement when the urge is felt, which can also occur in adults. Other conditions that affect digestion and cause constipation include dehydration, malignancy (cancer) and inflammation.

Gastrointestinal or digestive conditions, such as irritable bowel syndrome, colon cancer, anal fistula, and ileus (bowel paralysis) or obstruction can cause constipation. Chronic laxative use can cause the bowel to become dependent on laxatives in order to pass stool and lead to constipation when laxatives are stopped. Constipation with no known cause is called idiopathic constipation.

Constipation can also result from conditions that occur in other body systems, such as pregnancy and certain types of spinal cord injury. In some cases, an underlying condition, such as bowel obstruction, is life threatening.

Lifestyle and dietary causes of constipation

Constipation can be caused by lifestyle, diet or other conditions including:

• Advanced age

• Delaying bowel movements (ignoring the urge to have a bowel movement)

• Lack of physical activity

• Low-fiber diet

• Not drinking enough fluids

• Pregnancy

• Stress or anxiety

• Travel (travel-related constipation)

Gastrointestinal causes of constipation

Constipation may occur due to conditions of the digestive tract including:

• Anal fistula (abnormal connection or tunnel between the anus and the buttocks)

• Bowel (intestinal) obstruction

• Colonic inertia (abnormal nerve and muscle function in the colon)

• Colorectal cancer

• Dehydration from excessive vomiting or diarrhea

• Digestive tract surgery

• Diverticulosis or diverticulitis (inflammation of an abnormal pocket in the colon)

• Food intolerances or allergies such as to milk products

• Hirschsprung’s disease (caused by a neurological birth defect that leads to severe constipation and intestinal obstruction in newborns and infants)

• Irritable bowel syndrome (IBS; digestive discomfort that does not cause intestinal damage or serious disease)

• Pelvic floor dysfunction

Other causes of constipation

Constipation can be caused by neurological, metabolic and other conditions including:

• Depression

• Diabetes (chronic disease that affects your body’s ability to use sugar for energy)

• Eating disorders

• Hypercalcemia (high blood calcium)

• Hypothyroidism (underactive thyroid)

• Multiple sclerosis (disease that affects the brain and spinal cord causing weakness, coordination, balance difficulties, and other problems)

• Parkinson’s disease (brain disorder that impairs movement and coordination)

• Spinal cord injury

• Stroke

• Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)

• Uremia (high levels of nitrogen-type waste in the blood due to impaired kidney function)

Medications that cause constipation

Constipation can also be caused by certain medications including:

• Anesthetics

• Antacids that contain calcium and aluminum

• Anticonvulsants

• Antidepressants

• Calcium channel blockers for high blood pressure

• Diuretics

• Iron supplements

• Laxative abuse

• Narcotics

• Parkinson’s disease medications

• Tranquilizers

What are the potential complications of constipation?

In some cases, constipation can be caused by a serious condition of the gastrointestinal tract, such as bowel obstruction. It is important to contact your health care provider if you develop persistent constipation that lasts more than a few days. Once the underlying cause is diagnosed, following the treatment plan outlined by your doctor can lower your risk of potential complications including:

• Anal fissure

• Fecal impaction

• Hemorrhoid

• Peritonitis and shock from intestinal obstruction

• Rectal bleeding

• Rectal prolapse