Constipation Signs and Symptoms

What Is Constipation?

Although constipation means different things to different people, the symptoms of constipation are best described as a perception of abnormal defecation that may include decreased frequency of bowel movements, straining and/or painful defecation, or passage of hard stools.  Doctors often consider decreased frequency to be the most important of the symptoms of constipation, with constipation defined as existing when someone has less than three bowel movements per week.

Constipation is more common in women than men, and may affect up to 20% of the population.  Additionally, occurrence of constipation increases with increasing age.

Treatment of Constipation

If constipation is long-standing, is not worsening over time, and lacks associated “red flag” symptoms of blood in the stools, abdominal pain, or weight loss, then at-home treatment without formal medical evaluation may be appropriate.  First, an increase in dietary fiber to between 20 and 30 grams/day is the mainstay of successful treatment for most patients with constipation.  Fluid intake should be at least 1500 ml/day, and regular moderate exercise should be performed.  “Training your bowels” is frequently beneficial, and a gentle attempt at defecation 30 minutes following breakfast each day may be helpful.

Bran powder – Between one and two tablespoons of bran powder twice daily mixed with fluids or sprinkled over foods is a simple way of providing 10-20 grams per day of fiber

Fiber supplements – A variety of fiber supplements are available.  All usually work well, though some brands are more “soluble” (e.g. Citrucel, Benefiber), and are usually better tolerated, resulting in less bloating and gas.  The amount of fiber supplement needed is variable, ranging from 1-2 teaspoons/day to 1-2 tablespoons/day in most cases.  It is always best to start with a lower dose and increase slowly over time.

Oxmotic laxatives – These laxatives, e.g. Miralax (17 grams/8 oz water), Lactulose (15-30 ml/day), Sorbitol (15-30ml/day), Milk of Magnesia (15-30 ml/day) are effective in treating constipation, and may be used safely independently, or in combination with fiber supplementation.  It is important to consume adequate amounts of adequate liquids (at least 1500 cc/day) to avoid dehydration when using osmotic laxatives.

Emollient laxatives – Docusate sodium (50-200 mg/day) or mineral oil (1-2 tablespoons/day) may be given to promote stool softening, to be used periodically as needed.

How The Colon Works

The primary function of the colon is the storage and transport of waste.  This waste (the end product of food after nutrients have been removed by the small intestine) is in a primarily liquid form when it arrives in the colon, which then transforms it into solid waste by an active process of resorption of fluid and electrolytes.  The transport of this waste passes through specific segments of the colon by rhythmic contractions called peristalsis.  The very end of the colon, the rectum, acts as a final storage area until defecation occurs.  This entire process is complicated, involving both voluntary and involuntary (automatic) mechanisms.  Any step of the process of defecation, if abnormal, can result in constipation.

Causes Of Constipation

There are multiple steps involved in normal defecation, and therefore are many potential causes of constipation.  The vast majority of people with symptoms of constipation have relatively mild  symptoms which cannot be attributed to any specific structural abnormality, abnormal motility, underlying disease, or extrinsic inhibitory influences such as the use of certain medications.  Many people with mild constipation simply do not consume adequate dietary fiber and/or liquids.  Additionally, many people ignore nature’s “call to stool” which may result in a more difficult to pass stool later on.

Lifestyle – low fiber

inadequate fluids

ignoring impulse to defecate

lack of exercise

Structural  – Anorectal disease (fissure, thrombosed hemorrhoid, retocele, rectal prolapse)

Outlet obstruction (pelvic floor dysfunction)

Colon cancer

Colonic stricture (diverticular disease, post-radiation, poor blood flow)

Dysmotility – Colonic inertia (poor colonic contractions)

Irritable Bowel Syndrome

Underlying disease – Hypothyroidism (low thyroid function)

Hypercalcemia (high calcium)

Chronic renal (kidney) failure

Diabetes

Spinal cord lesions

Multiple Sclerosis

Parkinson’s disease

Hirschsprung’s disease

Autonomic neuropathy (poor nerve conduction)

Amyloidosis

Dermatomyositis

Progressive systemic sclerosis

Dementia

Medications – (Anticholinergics) -Antidepressants

Antihistamines

Antiparkinsonian drugs

Neuroleptics

(Antihypertensives) – Calcium channel blockers

Clonidine

(Cation-containing agents) – Iron supplements

Calcium supplements

Aluminum-containing antacids

Sucralfate

(Opiates) – Morphine

Codeine

Diphenoxylate

When To See A Doctor

Constipation is extremely common, and not everyone, especially those with mild chronic symptoms of constipation, needs to see a doctor.  However, if constipation occurs abruptly or progesses over a few weeks or months, then medical evaluation is important.  Additionally, if symptoms of blood in the stool, abdominal pain,or weight loss occur, or if there is a family history of colon cancer, then examination by a licensed physician is mandatory.

Tests to Identify Causes of Constipation

Because there are many potential causes for constipation, there exist a variety of available diagnostic tests.  Blood tests are needed to diagnose diabetes, hypothyroidism, or electrolyte imbalances.  A colonoscopy can definitively rule out colon cancer and colonic strictures.  A motility study, the Sitzmark study, can diagnose colonic inertia (poorly contracting colon).  Anorectal mannometry (a test of anorectal pressures) and defecography (functional imaging of rectum) may identify outlet obstruction,  (pelvic floor dysfunction)

Summary

Constipation is a common symptom affecting up to 20% of the general population.  If symptoms of constipation are mild and unchanging over a long period, then it is reasonable in most otherwise healthy individuals to treat constipation at home with dietary and behavioral modification, use of fiber supplementation, and other laxatives periodically as needed.  If the symptoms of constipation are poorly responsive to treatment, worsens over time, or is associated with pain, weight loss, or blood in the stools, then evaluation and treatment by a licensed doctor is essential.