Irritable bowel syndrome, or IBS, is a common condition that affects between 25 and 55 million Americans, the majority of whom are women. The condition most often occurs in people in their late teens to early 40s.
In essence, the condition is a combination of abdominal discomfort or pain and altered bowel habits: either altered frequency (diarrhea or constipation) or altered stool form (thin, hard, or soft and liquid).
We all have stomachaches and trouble going to the bathroom once in a while, but for people with IBS, the chronic pain and discomfort can be disabling.
Along with abdominal cramping and discomfort, IBS symptoms include:
Constipation -- the stool comes out either lumpy or hard
Diarrhea -- the stool comes out loose or watery
Alternating bouts of constipation and diarrhea
Bowel movements that feel uncontrollably urgent, difficult to pass, or incomplete
IBS is not a life-threatening condition and it does not make a person more likely to develop other colon conditions, such as ulcerative colitis, Crohn's disease, or colon cancer, or any diseases of the heart or nerves. Yet IBS can be a chronic problem that can significantly impair quality of life in those that have it. For example, people with IBS miss work three times more than people without IBS and the condition is associated with absenteeism from school, decreased participation in activities of daily living, alterations of one's work setting (shifting to working at home, changing hours), or giving up work altogether.
What Are the Symptoms of IBS?
Among the symptoms associated with IBS are:
Diarrhea (often described as violent episodes of diarrhea).
Constipation alternating with diarrhea.
Abdominal pains or cramps, usually in the lower half of the abdomen that are aggravated by meals and relieved by having a bowel movement. Often the person has more frequent bowel movements when they have pain and the stools are looser.
Excess gas or bloating.
Harder or looser stools than normal (rabbit like pellets or flat ribbon stools).
Visible abdominal distension.
Some people with IBS have other symptoms not related to their digestive tract, such as urinary symptoms or sexual problems.
People with IBS have traditionally been described as having "constipation-predominant," "diarrhea-predominant," or an alternating pattern of constipation and diarrhea. Each type represents about a third of the overall IBS population.
What Causes IBS?
Two hundred years after the condition was first described, experts still don't completely understand what causes IBS symptoms.
Many experts think that it is a problem of bowel motility -- the muscles in the bowels don't contract normally -- affecting the movement of stool. But some studies don't show that the poor bowel motility correlates with symptoms. Also, drugs that alter motility don't seem to benefit most people with IBS.