Irritable bowel syndrome (IBS) is a common condition characterized by abdominal discomfort associated with altered bowel movements.
Recent research has shown that many symptoms of IBS are related to hyperactivity of the nerves found in the wall of the gastrointestinal tract. These nerves are distinct from the nerves found in your spinal cord and brain. In some individuals, IBS may arise from how the gut nerves communicate with your brain, or how your brain processes information once it is received from your gut.
In Western countries, IBS seems to affect women twice as often as men. IBS is very common, affecting up to 15 percent of the United States population. Most individuals with IBS develop their first symptoms before the age of 40, with many patients recalling the onset of symptoms occurring during childhood or young adulthood. There appears to be a familial component, as many patients with IBS will report having a family member with similar symptoms. Less commonly, the symptoms of IBS develop after a severe intestinal infection; this is called postinfectious IBS.
It is important to note that IBS is very different from a similarly named disease, inflammatory bowel disease (IBD)
See animation: Colonic Motility, Normal and the Irritable Bowel.
Irritable Bowel Syndrome (IBS) Types
There are three subcategories of IBS:
- Mostly diarrhea and abdominal discomfort (IBD-D)
- Mostly constipation and abdominal discomfort (IBS-C)
- Alternating loose stools and constipation with abdominal discomfort (IBS-mixed)
Irritable Bowel Syndrome (IBS) Symptoms
Symptoms and signs of IBS.(Click to Enlarge)
The main symptom of IBS is abdominal pain or discomfort associated with a change in your bowel habits. Patients with IBS may describe the abdominal discomfort in different ways, such as sharp pain, cramping, bloating, distention, fullness or even burning. The pain may be triggered by eating specific foods, following a meal, emotional stress, constipation or diarrhea.
Other symptoms include:
- Feeling of incomplete evacuation
People with IBS may also experience symptoms unrelated to the intestine, including:
Some people with IBS are able to tolerate their symptoms very well and go about their regular routine. Other patients find that their symptoms prevent them from going to work or doing other activities. Often, stress is associated with the onset of symptoms; the symptoms then improve when the stress is gone. Other patients may experience random IBS episodes that have no obvious triggers. Still others may have long periods of symptoms, followed by long symptom-free periods.
IBS Diagnosis at Johns Hopkins
A doctor diagnoses IBS based solely on the presence of specific symptoms and the patient’s clinical history. International research groups have helped define the symptoms that diagnose of IBS. There are currently no laboratory tests or imaging tests that diagnose IBS. A trained and experienced gastroenterologist can distinguish the classic symptoms of IBS from other symptoms that might prompt an evaluation to exclude other diseases.
Physical Exam and Blood Test
A diagnosis of IBS begins with a comprehensive physical exam during which you describe your symptoms and medical history. Your doctor may diagnose IBS based on your symptoms and history but will also look for red flags that suggest the need to look for a different diagnosis. Red flags include:
- Onset of symptoms in someone who is more than 50 years of age
- Evidence of gastrointestinal bleeding
- Pain or other symptoms that awaken you in the middle of the night from sleep
If you have symptoms of IBS and a red flag symptom, you will probably need a more complete investigation. You may require further testing, depending on what your symptoms are.
IBS Treatment at Johns Hopkins
The goal of treatment for IBS is to provide relief from your symptoms. Your exact course of treatment will depend on the type and severity of your symptoms. Learn more about irritable bowel syndrome treatment at Johns Hopkins.