Chronic constipation is a common condition that is characterized by difficult, infrequent, or perceived incomplete evacuation of bowel movements. Symptoms of constipation include having less than 3 bowel movements per week, straining, hard stools, incomplete evacuation and inability to pass stool. Patients with chronic constipation do not have diarrhea unrelated to using laxatives. The prevalence of chronic constipation ranges from 2-28%. Up to 63 million people in North America meet the diagnostic criteria for chronic constipation. Epidemiologic studies demonstrate that the prevalence of constipation increases with age and is more common in women than men.
What Causes Chronic Constipation?
There are many different causes of chronic constipation. It can be due to structural lesions of the colon (e.g., colon cancer, colon stricture or narrowing), medical conditions such as diabetes, thyroid disorders, Parkinson’s disease, or pregnancy, or due to medications such as pain medications (narcotics), blood pressure medications (calcium channel blockers), anti-seizure medication, and antispasmodics. In these cases, switching to a new medication can improve the symptoms. In people over 50, a more serious bowel disease or a structural disorder could cause the onset of constipation, so it is important to see a health professional to rule out any serious causes.
Chronic constipation that is not due to “secondary” causes, such as other medical conditions or medications, is referred to as “functional constipation.” The three main causes of functional constipation are normal transit constipation, slow transit constipation, and defecatory or evacuation disorders. In normal-transit constipation, the rate of stool passage through the colon and stool frequency are normal, but patients perceive that they are constipated. Changes in the water content of the colon may also play a role in this type of constipation. In slow-transit constipation, passage of stool through the colon is slower than normal. Defectory disorders that can cause constipation include dyssynergic defecation, rectal prolapse (protrusion of rectal tissue through the anal opening), and rectocele (outpouching of the rectum). In dyssynergic dysfunction, also referred to as pelvic floor dysfunction or anismus, there is ineffective coordination of the pelvic floor, abdominal, rectal, and anal sphincter musculature in the evacuation mechanism.
How is Chronic Constipation Diagnosed?
The presence of at least 2 of the six following symptoms over the past 3 months are diagnostic of chronic constipation: straining, hard stools, sensation of incomplete evacuation, sensation of anorectal blockage, use of manual maneuvers to facilitate evacuation of stool, and less than 3 bowel movements per week. These symptoms must occur at least 25% of the time. The main symptom that differentiates functional constipation from irritable bowel syndrome (IBS) with constipation is abdominal pain which is a more predominant symptom of IBS.
Identification of “secondary” causes of constipation should be considered, particularly in patients who present with “red flags” such as unintentional weight loss, blood in the stool, onset of symptoms after the age of 50, and family history of colon cancer. Diagnostic tests such as a colonoscopy (examination of the colon) may be indicated. In patients without red flags, limited and judicious use of diagnostic tests is recommended. “Slow transit” constipation can be confirmed by several specialized studies, including sitz marker colon transit test, radionuclide scintigraphy and wireless motility capsule. A defecatory disorder can be confirmed with an anorectal manometry with balloon expulsion or evacuation test and/or a defecogram (a type of X-ray study of the rectum). Your doctor can determine if these diagnostic tests are indicated.
What Can I Do to Improve Constipation?
It is important to understand that some individuals use the bathroom less often than others and this can be the way your body functions normally. If you do suffer from bothersome symptoms of chronic constipation, a high fiber diet or fiber supplements, such as psyllium, is recommended particularly for milder forms of constipation and can help to ease stool passage and normalize bowel movements. Increasing fluid intake and exercise are usually recommended but may have limited efficacy. In more moderate to severe constipation, medications are usually needed. Over-the-counter laxatives can increase stool frequency and soften hard stools. Lubiprostone is a calcium channel activator that increases electrolyte and fluid secretion into the lumen of the intestine and accelerate transit time of stool through the bowel, and thus improves constipation symptoms.
In cases of dyssynergic defecation, anorectal biofeedback is the most effective treatment. In more severe cases of rectal prolapse and rectocele, surgery may be indicated.
What We Are Doing at CNS:
Research Studies: Clinical research is essential in advancing our understanding of biological and psychological mechanisms underlying functional gastrointestinal disorders and constipation and to develop more effective treatments. The only way these studies can be performed is when affected patients are willing to participate in them. If you are interested in these studies, Click here for further information.
Links and Information on IBS:
The International Foundation for Functional Gastrointestinal Disorders (IFFGD): is a nonprofit education and research organization founded in 1991. IFFGD addresses the issues surrounding life with gastrointestinal functional and motility disorders and increases the awareness about these disorders among the general public, researchers, and the clinical care community. www.iffgd.org/