Diseases and Conditions

Irritable Bowel Syndrome

Irritable Bowel Syndrome

Symptoms

Although IBS has a number of symptoms, including diarrhea and constipation, one symptom typically predominates [Table 1]. Sometimes diarrhea is the chief complaint during an irritable bowel attack. In such cases, patients may feel a strong need to relieve themselves many times throughout the day, and then pass loose, watery stools. When constipation predominates, patients may have fewer than three bowel movements a week, and pass small, hard stools after straining on the toilet. Some IBS patients experience alternating bouts of diarrhea and constipation.

Others with irritable bowel feel as though they are not able to void completely. They may also feel full and bloated, and pass excessive amounts of gas. Most patients experience some degree of abdominal pain or discomfort that usually is relieved after a trip to the bathroom.

Table 1.   Characteristics of IBS
Diarrhea-predominant IBS
More than three bowel movements per day
Loose watery stools
Urgency more than 25% of the time
Pain-predominant IBS
Abdominal pain
Cramping or aching that is relieved by a bowel movement or flatulence
Bloating-predominant IBS
Feeling full or bloated
Excessive flatulence
Predominant rectal dissatisfaction
Feeling of incomplete bowel voiding
Constipation-predominant IBS
Fewer than three bowel movements per week
Lumpy hard stools
Straining during bowel movements
IBS with alternating bowel habit
Alternating episodes of diarrhea and constipation

Risk Factors

About 15% of Americans have IBS, but many do not seek treatment. Although IBS affects both sexes, it is reported more frequently in women. Women with IBS seem to have more symptoms during their menstrual periods, which suggests that reproductive hormones may increase IBS symptoms. Although it has long been thought that anxiety, depression, and other mental illnesses were more common in those with IBS, recent studies have found this to be untrue. The psychological distress doctors assumed was the cause of IBS actually appears to be the result of coping with the overwhelming negative impact IBS can have on one's life. Reliable research now suggests IBS to be strictly a physical problem that is sometimes accompanied by a psychosocial component.