What is Constipation?
Constipation is defined as infrequent or hard pellet stools, or difficulty in evacuating stool. If you go one day without a bowel movement it does not necessarily mean you are constipated. In fact, everyone has a slightly different bowel habit (which varies in and of itself depending on the day, what you eat, and age), so what is routine for one person may very well be different compared to someone else. Constipation typically involves multiple days without a bowel movement, great difficulty during bowel movements, and it is often a chronic problem. When this occurs, medical attention should be sought to find the cause of constipation.
What Causes Constipation?
By the time food reaches the large intestine (colon), it has been mostly digested. One of the colon’s main jobs is to withdraw water from the remains of food (now stool), so by the time it reaches the rectum there is a soft, formed stool that can pass as a bowel movement. However, if the transit in the colon is slow, meaning the colon doesn’t contract properly and stool spends a long time in the colon, too much water can be extracted from the stool. This causes the stool to become hard and difficult to expel, causing constipation. Slow transit can also be caused by:
- Pregnancy
- Certain medications, especially narcotics
- Hormonal imbalances from diabetes, thyroid disease, or other issues
- The abuse of laxatives
- Travel and stress
- Neurological problems or diseases that interfere with the signals associated with moving the bowels
Constipation is not always caused by slow transit. Additional causes of constipation include:
- Problems with the muscles that help promote normal bowel function (anismus, dyssynergia, or weakened pelvic muscles)
- Bowel obstruction or narrowing of the colon (bowel stricture)
- Tumors
- Colorectal cancer
- Advanced diverticulosis or diverticulitis
- Rectocele (an outpouching of the rectum)
Additionally, irritable bowel syndrome (IBS) is often associated with symptoms of constipation. More information on IBS here.
What are Some Possible Complications of Chronic Constipation?
- Impaction: a buildup of fecal matter that has become hard, dry, and stuck in the colon. Impactions can be difficult or sometimes impossible to pass alone. Often enema, manual removal (by trained professionals), or rarely, surgery, is needed to remove impacted stool.
- Anal fissure: a small tear in the tissue that lines the anus. This tear can cause pain and/or bleeding.
- Hemorrhoids
- Rectal prolapse: the protrusion of all or part of the rectum through the anus as a result of over-stretching of the rectum from chronic amounts of large stool
What Should I Do if I Have Constipation?
If you experience regular constipation, you should be evaluated for the presence of a digestive disorder or disease that could be causing these symptoms. During your evaluation, you'll be asked about your symptoms, how often they occur, and if they're accompanied by pain or other symptoms. You'll also be asked to provide a medical history to look for clues. A physical exam and blood tests are most often additional helpful first steps. In some instances, no further testing is needed and lifestyle modification or medication is tried.
If warranted, there is a variety of testing available to diagnose the cause of constipation. An in-office visual and tactile exam of the anus (called an anoscopy, or rectal exam) can check for suspected hemorrhoids, anal fissure, and problems with rectal muscles. A sigmoidoscopy uses a sigmoidoscope (a light, flexible endoscope) to visualize the sigmoid colon and rule out mechanical blockages, such as tumors. Colonoscopy is not often indicated for constipation only, but can rule out advanced diverticulosis or diverticulitis and colorectal cancer. In severe circumstances, anorectal manometry or defecography are used to rule out muscular and structural causes of constipation.
What Treatments are Available for Constipation?
Treatment for constipation depends on the underlying cause of the constipation. For those with mild to moderate chronic constipation, dietary changes and/or medication are often helpful. A high fiber diet is recommended for those with chronic constipation (fruits, vegetables, whole grain breads, bran cereals). If dietary modification is not adequate and constipation persists, laxatives and/or stool softeners may be tried. Some people with more severe symptoms use enemas or medication used to stimulate secretion of water in the colon periodically.
For those with severe constipation caused by a less common underlying cause, treatment may differ. Medication may still be prescribed, but additional treatments or therapies may also be tried. For example, patients with severe constipation caused by problems with the muscles that promote normal bowel function are sometimes prescribed anorectal biofeedback therapy, where they learn neuromuscular conditioning to re-train their muscles to behave more normally.
