Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS) is a disorder of intestinal movement and sensation. IBS is not associated with inflammation, and it does not lead to more permanent harm or progress to more serious conditions.
The cause of irritable bowel syndrome is not known. The colon normally contracts in response to eating. With irritable bowel syndrome, the muscles in the colon do not function normally and may spasm. Individuals with IBS may possess a colon that is more sensitive than normal and reacts more strongly to food, medication, and other factors.
Despite these uncertainties, there is increasing evidence that the causes may be different in different people and that both food allergies and “overgrowth” of certain bowel bacteria may contribute to the symptoms. There is also fairly strong evidence that irritable bowel syndrome can follow an episode of infectious diarrhea (often called gastroenteritis or “food poisoning”). While it is not yet certain that infection actually causes irritable bowel syndrome, many gastroenterologists think that this might be the case.
Once established, in susceptible people, the following may worsen symptoms of IBS:
- Psychological stress from any source
- Menstrual periods
- Large meals or fatty foods
- Excess gas
A risk factor is something that increases your chances of getting a disease or condition.
Risk factors for IBS include :
- Sex: Female
- Family members with IBS
- Sexual abuse
- Domestic violence
Irritable bowel syndrome symptoms usually come and go. Symptoms range in intensity from mild to severe.
- Abdominal cramps
- Gas and bloating
- Pain that resolves with a bowel movement
- Loose stools
- Alternating diarrhea and constipation
- Urge to move bowels again immediately following a bowel movement
- Mucus in the stool
The doctor will ask about your symptoms and medical history, and perform a physical exam. In many cases this is sufficient to make the diagnosis. Since there is no diagnostic test for irritable bowel syndrome doctors have developed standardized criteria for deciding who does and who doesn’t have the disorder. However, diagnostic tests are often performed to rule out other diagnoses having similar symptoms. These may include:
- Analysis of a stool sample to check for blood or evidence of inflammation
- Blood tests
- Barium enema–injection of fluid into the rectum that makes your colon show up on an an x-ray so the doctor can see abnormal spots in your colon
- Flexible sigmoidoscopy –a thin, lighted tube inserted into the rectum to examine the rectum and the lower colon
- Colonoscopy–a thin, lighted tube inserted through the rectum and into the colon to examine the lining of the entire colon
- Other tests to rule out other medical conditions
There is no cure for IBS. Treatment focuses on controlling symptoms.
The following dietary interventions may help control your Symptoms:
- Keep a food diary, listing what you eat and what reaction occurs. Discuss the findings with your doctor or a dietitian. Since food allergy probably plays a role in the symptoms that some people with irritable bowel experience, you may wish to consult an allergist or a gastroenterologist familiar with diagnosis of food allergies. In most cases, a careful food diary will be more useful in diagnosing allergies than will any kind of testing.
- Make gradual changes to your diet and record the results.
- Avoid foods that have provoked symptoms more than once. A dietitian can help you choose substitutes for offending foods.
- Avoid the following foods and drinks that may provoke Symptoms:
- High-fat foods
- Spicy foods
- Dairy products
- Other gas-producing foods
- Large amounts of alcohol or caffeine
- Eat foods that may reduce the chance of spasm, such as:
- Fruits and vegetables
- Whole grains and other high-fiber foods (Note: More fiber may increase gas and bloating until your body adjusts.)
- Eat smaller meals more often or smaller portions.
- Eat slowly and try not to swallow air.
- Drink plenty of water (at least two liters per day) to help reduce constipation.
Techniques to reduce stress include:
- Stress management techniques
- Relaxation techniques
- Counseling to help develop coping skills
- Exercise (also improves bowel function)
Exercise not only helps reduce stress, but it may also directly improve bowel function.
Depending on the severity of your symptoms and whether you predominantly suffer from diarrhea or constipation, your doctor may recommend one or more of the following types of medications:
- An antibiotic. Recent data suggests that brief treatment with the non-absorbed antibiotic, Rifaximim, can improve symptoms for at least several months. More studies will be necessary to see whether benefit persists or retreatment is necessary.
- An antispasmotic agent (eg, dicyclomine)
- A high-fiber bulking agent (eg, psyllium)
- An antidiarrheal agent (eg, loperamide)
- A low-dose antidepressant
- A pain reliver (eg, acetaminophen (Tylenol))
- Findings from a recent clinical trial showed modest benefit of acetaminophen for treatment of crampy abdominal pain in 2000 patients with IBS.*
Many doctors favor a newer class of medications called serotonin receptor agonists and antagonists for the most serious cases, particularly in women. Tegaserod is prescribed for constipation and alosetron for diarrhea (but under limited circumstances).
“Probiotics” (preparations containing “helpful” bacteria and yeasts) have been shown to be helpful in some people and could be tried under medical supervision.
There are no guidelines for preventing IBS because the cause is unknown.