All about IBS (Irritable bowel syndrome) - By Arun Aggarwal

Irritable bowel syndrome (IBS) is a chronic condition of the digestive system. Its primary symptoms are abdominal pain and changes in bowel habits (eg, constipation and/or diarrhea).

IRRITABLE BOWEL SYNDROME CAUSES —

• One theory suggests that IBS is caused by abnormal contractions of the colon and intestines (hence the term "spastic bowel," which has sometimes been used to describe IBS). Vigorous contractions of the intestines can cause severe cramps.
• Some people develop IBS after a severe gastrointestinal infection (eg, Salmonella or Campylobacter, or viruses).
• People with IBS who seek medical help are more likely to suffer from anxiety and stress than those who do not seek help. Stress and anxiety are known to affect the intestine.
• Food intolerances are common in patients with IBS, raising the possibility that it is caused by food sensitivity or allergy. 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). These foods increase intestinal gas, which can cause cramps.
• Many gastroenterologist believe that IBS is caused by heightened sensitivity of the intestines. The medical term for this is "visceral hyperalgesia." 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.

SYMPTOMS — IBS is more common in women than in men. The most common symptom of IBS is abdominal pain in association with changes in bowel habits (diarrhea and/or constipation).

Abdominal pain — Abdominal pain is typically crampy and varies in intensity. 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.

Changes in bowel habits — Altered bowel habits are the other symptom typical of IBS. This can include diarrhea, constipation, or alternating diarrhea and constipation.

Other symptoms — Other symptoms of IBS include bloating, gas, and belching.

IRRITABLE BOWEL SYNDROME DIAGNOSIS

Tests — Most clinicians order routine blood tests in people with suspected IBS; these tests usually come back normal, but they can help rule out other medical conditions.

Some gastroenterologists also order more invasive tests, such as sigmoidoscopy or colonoscopy.

IRRITABLE BOWEL SYNDROME TREATMENT — There are a number of different treatments and therapies for irritable bowel syndrome (IBS). Treatments are often given to reduce the pain and other symptoms of IBS, and it may be necessary to try more than one combination of treatments to find the one that is most helpful for you.

Diet changes — It is reasonable to try eliminating foods that may aggravate IBS.

Lactose — Many gastroenterologists recommend temporarily eliminating milk products, since lactose intolerance is common and can aggravate IBS or cause symptoms similar to IBS.

Foods that cause gas — Many foods are only partially digested in the small intestines. When they reach the colon (large intestine), further digestion takes place, which may cause gas and cramps. Eliminating these foods temporarily is reasonable if gas or bloating is bothersome.

The most common gas-producing foods are legumes (such as beans) and cruciferous vegetables (such as cabbage, Brussels sprouts, cauliflower, and broccoli).

Increasing dietary fiber — Increasing dietary fiber (either by adding certain foods to the diet or using fiber supplements) may relieve symptoms of IBS, particularly if you have constipation. Fiber may also be helpful in some people with diarrhea-predominant symptoms since it can improve the consistency of stools.

A bulk-forming fiber supplement (such as psyllium or methylcellulose) may also be recommended to increase fiber intake since it is difficult to consume enough fiber in the diet. Fiber can make some people with IBS more bloated and uncomfortable. If this happens, it is best to decrease fiber intake and consider other laxative treatments for constipation.

Psychosocial therapies — Stress and anxiety can worsen IBS in some people. The best approach for reducing stress and anxiety depends upon your situation and the severity of your symptoms. Have an open discussion with your gastroenterologist about the possible role that stress and anxiety could be having on your symptoms, and together decide upon the best course of action.

Irritable bowel syndrome medications — Although many drugs are available to treat the symptoms of IBS, these drugs do not cure the condition. They are mainly used to relieve symptoms. The choice among these medications depends in part upon whether your primary symptom is diarrhea, constipation, or pain.

Anticholinergic medications — Anticholinergic drugs block the nervous system's stimulation of the gastrointestinal tract, helping to reduce severe cramping and irregular contractions of the colon.

Drugs in this category include dicyclomine (brand name: Bentyl), hyoscyamine (sample brand name: Levsin).

Antidepressants — While primarily used to treat depression, many tricyclic agents (TCAs) have a pain-relieving effect in people with IBS. The dose of TCAs is typically much lower than that used for treating depression. It is believed that these drugs reduce pain perception when used in low doses, although the exact mechanism of their benefit is unknown.

TCAs also slow movement of contents through the gastrointestinal tract and may be most helpful in people with diarrhea-predominant IBS.

Another class of antidepressants, the selective serotonin reuptake inhibitors (SSRIs), may be recommended if you have both IBS and depression.

Antidiarrheal drugs — The drugs loperamide (sample brand name: Imodium) or diphenoxylate-atropine (brand name: Lomotil) can help slow the movement of stool through the digestive tract. These medications are most helpful if you have diarrhea-predominant IBS.

Other medications

Alosetron — Alosetron (brand name: Lotronex) blocks a hormone that is involved in intestinal contractions and sensations. It is approved to treat women with IBS whose predominant symptom is diarrhea.

Lubiprostone — Lubiprostone (brand name: Amitiza) is available for treatment of severe constipation and IBS in women over 18 years who have not responded to other treatments. It works by increasing intestinal fluid secretion.

Linaclotide — Linaclotide (Linzess) has been approved for treatment of constipation and IBS in persons over 18 years who have not responded to other treatments. It works by increasing intestinal fluid secretion.

Antibiotics — The role of antibiotics in the treatment of IBS remains unclear. There are some patients whose IBS symptoms benefit from antibiotic treatment. Rifaximin has been approved for treatment of IBS without constipation.

Probiotics- uncertain role.