Irritable bowel syndrome
 

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder affecting approximately 10 to 20 % of the population. Although the condition cannot be cured, treatments are available to alleviate symptoms. 

 No single cause of IBS has been identified, although there are theories that gastrointestinal abnormalities, food intolerance, and psychological issues may be involved.

Many researchers believe that IBS is caused by heightened sensitivity of the intestines to normal sensations . This theory proposes that nerves in the bowels are overactive in people with IBS, so that normal amounts of gas or movement are perceived as excessive and painful.

 IBS usually begins in young adulthood. Women are twice as likely as men to be diagnosed with IBS. The hallmark of IBS is abdominal pain in association with altered bowel habits (diarrhea and/or constipation).

Abdominal pain 

 Abdominal pain is typically crampy, varying in intensity, and located in the lower left abdomen.  Some people notice that emotional stress and eating worsen the pain, and that having a bowel movement relieves the pain. Some women with IBS notice an association between pain episodes and their menstrual cycle.

Altered bowel habits

 Altered bowel habits are a second hallmark of IBS. This can include diarrhea, constipation, or alternating diarrhea and constipation. If diarrhea is the more common pattern, the condition is called diarrhea-predominant IBS; if constipation is more common, the condition is called constipation-dominant IBS.

   Diarrhea 

 The diarrhea of IBS causes frequent loose stools of small to moderate volume. Bowel movements usually occur during the daytime, and most often in the morning or after meals. Diarrhea is often preceded by a sense of extreme urgency and followed by a feeling of incomplete evacuation. About one-half of people with IBS also notice mucous discharge with diarrhea. Diarrhea occurring during sleep does not occur in IBS and suggests another diagnosis.

   Constipation 

 The constipation of IBS can last from days to months. Stools are often hard and pellet-shaped. Sometimes people do not feel empty after a bowel movement, even when the rectum is empty. This faulty sensation can lead to straining, sitting on the toilet for prolonged periods of time, and the use of enemas and laxatives for relief.

Other symptoms 

 Other symptoms include bloating, gas, belching, heartburn, difficulty swallowing, an early feeling of fullness with eating, and nausea.

 Several intestinal disorders have symptoms that are similar to IBS. Examples include malabsorption , inflammatory bowel disease , and microscopic and eosinophilic colitis .

Because there is no single diagnostic test for IBS, many clinicians compare a person's symptoms to formal sets of diagnostic criteria (such as the Rome or Manning criteria) . A medical history, physical examination, and select tests can help to rule out other medical conditions.

Medical history 

The medical history will include a discussion of the nature, duration, and severity of gastrointestinal and other symptoms. Sometimes a medical history reveals that dietary factors or drugs are actually causing a person's symptoms.

Physical examination 

 The physical examination is usually normal in people with IBS, but it can help detect or rule out conditions that mimic IBS.

Tests 

 Routine blood tests are usually normal, but they can help rule out other medical conditions. Sometimes, based upon certain symptoms or other factors in the medical history, a clinician will order thyroid function tests and/or stool tests to check for certain other conditions.

   Treatment is usually a long-term process; during this process, it is important to communicate with your healthcare provider about symptoms, concerns, and any stressors or home/work/family problems that develop.

Monitoring 

 The first step in treating IBS is usually to monitor symptoms, daily habits, and any other factors that may affect gastrointestinal function. This can help to identify factors that worsen symptoms in some people with IBS, such as lactose or other food intolerances and stress.

Dietary changes 

A number of foods are known to cause symptoms that mimic or aggravate IBS, including dairy products (which contain lactose), legumes (such as beans), and cruciferous vegetables (such as broccoli, cauliflower, Brussels sprouts, and cabbage).

 Increasing dietary fiber (either by adding certain foods to the diet or using fiber supplements) can relieve symptoms in some people with IBS, particularly people who have constipation .A bulk-forming fiber supplement (such as psyllium or methylcellulose ) may be recommended to increase fiber intake since it is difficult to consume enough fiber in the diet . Fiber supplements should be started at a low dose and increased slowly over several weeks to reduce the symptoms of excessive intestinal gas, which can occur in some people when beginning fiber therapy.

Psychosocial therapies 

 Stress and anxiety can worsen IBS in some people.  Patients should have an open discussion with their clinician about the possible role that stress and anxiety could be having on symptoms, and together decide upon the best course of action.

Medications 

Anticholinergic medications 

Antidepressants

Antidiarrheal drugs

Anxiolytic drugs

Alosetron

Tegaserod

Antibiotics

The choice among these medications depends in part upon whether a person has diarrhea, constipation, or pain- predominant IBS.  As a general rule, medications are reserved for people whose symptoms have not adequately responded to more conservative measures such as changes in diet and fiber supplements.

These measures help alleviate symptoms, but do not cure the condition. The chronic nature of IBS and the challenge of controlling its symptoms can be frustrating for both patients and healthcare providers.

HERBS AND NATURAL THERAPIES 

 A number of herbal and natural therapies have been advertised (especially on the internet) for the treatment of IBS. Unfortunately, there is no evidence supporting their benefit from carefully conducted studies.

 Although IBS can produce substantial physical discomfort and emotional distress, most people with IBS do not develop serious long-term health conditions. Furthermore, the vast majority of patients learn to control their symptoms and IBS does not decrease life expectancy.

Over time, less than 5 % of people diagnosed with IBS will be diagnosed with another gastrointestinal condition. It is important to work with a clinician to monitor symptoms over time. If symptoms change over time, further testing may be recommended.