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Irritable Bowel Syndrome (IBS or Spastic Colon)


What is Irritable Bowel Syndrome?

Common names for this condition include spastic colon, nervous colon, nervous stomach, mucous colitis and spastic colitis. Physicians often refer to this condition by the initials IBS. The typical symptoms of IBS include crampy abdominal pain, bloating, distention and abnormal bowel habits. There may be diarrhea, constipation or a combination of both. It is common for IBS to affect teenagers and young adults. Symptoms may even date back to early childhood. Occasionally the syndrome can start in middle age. The symptoms can wax and wane and return in periods of stress throughout a person’s lifetime.

What is the latest change in the understanding and treatment for IBS?

The latest change in the understanding of IBS is the role of bacterial overgrowth in the small intestine. This started by noticing that some patients with IBS developed the condition after a food or water born diarrhea illness. Studies of these patients found that they developed a number of problems after the original bacterial infection was gone. These included increased number of white blood cells in the lining of the intestine, increased permeability of the intestine (the medical term for “leaky gut”), and even more recent studies suggested that they had too many normal bacteria in their small intestine. The small intestine normally has very few bacteria and the large intestine (colon) has many bacteria.

Study of small intestinal motility or muscular action in these patients and others with IBS in whom no known "food poisoning" had occurred showed the following: the small intestinal activity that is responsible for keeping the intestine clean and keeping the bacterial counts low is damaged. Testing by cultures or an indirect method of testing for bacterial overgrowth, the lactulose breath test, showed evidence for bacterial overgrowth in the small intestine of many patients with IBS.

We now treat many patients for this problem with a new antibiotic that stays in the intestines and a motility agent that helps keep the bacterial counts down. We are doing research now to help refine this therapy and to see if this explains the extraintestinal symptoms of IBS: interstitial cystitis, restless legs syndrome, fibromyalgia, and chronic fatigue.

What is the role of stress and what is visceral hypersensitivity?

Stress is a major factor that plays a significant role in many patients who have IBS. Some people react to stress by getting tension headaches. People with IBS often get tension and pain in the abdomen in response to stress, anxiety and depression. People who are prone to IBS are affected by many stimuli to various levels of the nervous system. An overly sensitive neurological sensory system is a major component that contributes to IBS - this is often referred to as visceral hypersensitivity. This system is susceptible to the effect of stress.

What is abnormal in people with IBS?

Patients with IBS have an abnormal electrical system of their colon with a higher electrical cycling activity and are set up to be more contractile under various stimuli. Intense prolonged, spastic contractions of the colon occur in IBS. When two parts of the colon go into contraction, the colon in between becomes stretched out like a balloon. As a result the abdomen will feel bloated or distended. The sensory or pain nerve fibers get stimulated when there is a stretching of the colon wall. The brain perceives this as pain. The brain actually communicates with the gut through a complex series of nerves that is called the Brain-Gut connection. These connections are abnormal in IBS and the location can be in either the brain or the gut. Stress, depression and various chemical imbalances can affect the Brain-Gut connection. The nerves and muscles of the intestine that are abnormal in IBS may be affected directly by specific food that is eaten. Some researchers feel that a viral infection is responsible for a long-lasting disturbance of the Brain-Gut system. It is also possible that this disturbance is inherited or occurs as the fetus develops in the uterus.

With abnormal nerves and heightened responses to digestive hormones, IBS patients have abnormally strong and prolonged contractions of their intestines compared to people without IBS. These strong contractions of the colon help explain why people with IBS often have an urge to have a bowel movement 15 to 30 minutes after eating. The bowel movement is often diarrhea because the muscular contractions are spastic and move the waste material quickly from the right side of the colon to the left side and does not allow for the time required to absorb the water and form the stool. When colon spasms relaxes in one area, the stool can rush into another segment and with a sudden contraction it will come out as diarrhea. If the colon remains in spasm for too long, the stool that is staying in one area can get dried out because the colon is a very effective sponge to wick out or absorb water. This can results in small hard stools, which can alternate with diarrhea.

There may be different levels of the Brain-Gut connection that are affected and result in a similar set of symptoms in people labeled with IBS. A combination of the abnormal Brain-Gut system, visceral hypersensitivity and hyperactive intestines appear to be responsible for IBS.

Why is IBS called a syndrome and not a disease?

IBS is called a syndrome rather than a disease because it is comprised of a group of symptoms and there are no specific blood tests, endoscopic findings or biopsy results that are diagnostic for IBS. A syndrome may feel like a disease but you cannot die from IBS like you can from a disease. The symptoms of IBS can be so oppressive that it can severely impact one’s life.

How is IBS diagnosed?

Abdominal pain or discomfort is the hallmark symptom of IBS. In order to make a clinical diagnosis of the IBS there should be a change of bowel habits and all other medical conditions that could produce these gastrointestinal symptoms need to be excluded. Other symptoms that occur with irritable bowel syndrome many include relief of pain with defecation, bloating, passage of mucus and an incomplete sense of evacuation. In this case one may feel never completely empty and it may be necessary to return to the toilet multiple times. There may also be a sense of urgency and need to strain. Other symptoms unrelated to the digestive system occur frequently and include anxiety, depression, back pain, urinary frequency and discomfort with sexual intercourse.

What conditions can cause similar symptoms?

A common condition that can cause the same symptoms as IBS is lactose intolerance. Lactose is the sugar found in all dairy products and is the most common cause for excessive gaseousness. Wheat or gluten protein allergy (celiac sprue) or wheat intolerance are other conditions that can result in excessive gas, bloating and diarrhea. Since inflammation of the colon can cause similar symptoms as IBS, a variety of diseases such as ulcerative colitis, Crohn’s disease and infections should be looked for when suspected. Colon cancer needs to be excluded by appropriate testing. when people have sudden onset of IBS symptoms or when the symptoms begin when they are over 40 years of age. A complete medical evaluation is necessary for anyone with diarrhea after bedtime, bleeding or weight loss.

Unfortunately the condition is a life-long problem that can come and go. Since the condition does not have a specific known cause there cannot be a simple cure. There are many things, however, that can be done to make life manageable and suppress the symptoms.

What treatments are used for IBS?

Treatment includes changes in diet, changes in behavior and stress management and use of certain medications. The amount of fiber consumed, food intolerance and other dietary facts often play a role in IBS. The addition of fiber to the diet will often help constipation and alternating constipation-diarrhea forms of IBS. When the person only has diarrhea, fiber should be added even more gradually to the diet. The colon acts in a more coordinated fashion and requires less forceful contractions to move along the stool, which has more bulk that the fiber helps provide. It may take several weeks to see the benefit and there will be an initial accommodation to extra gas and flatulence that will generally be a side effect of the fiber. An example of a high fiber diet would be one that includes high fiber cereal, whole grain bread, 3 servings of vegetables and 2 servings of fruit each day. Everyone’s colon has its own dose of fiber to make it work well so there will be some experimentation required.

Specific dietary factors can play into the performance of the intestine. In addition to lactose and gluten, other dietary sugars that create gas and diarrhea include sorbitol and mannitol that may be used as artificial sweeteners. Additives such as Nutrasweet, MSG and sulfites may be a problem for others. Caffeine is a profound stimulant to the intestinal muscles and contributes to nervous activity of the brain and the gut. Elimination of coffee, tea and chocolate will often go a long way to help reduce the symptoms of IBS. Reduction of fat in the diet is very important since it helps decrease the amount of cholecystokinin produced. Swallowing air may be a factor in bloating and occurs by rapid eating, talking while eating, chewing gum and drinking soda. Certain foods such as beans are naturally gassy because the fiber content does not breakdown and bacteria ferment it. Enzyme pills are available to help with this. The following fruits and vegetables are naturally prone to producing gas. Cabbage, beans, broccoli, cauliflower, onions, prunes and apples are some examples. It is also helpful to eat at regular intervals and not to eat the majority of your calories at one time since this will lead to excessive stimulation of the gut. Increasing water consumption is important, especially when there is a tendency to have constipation.

A recent article showed that excess gas and symptoms of IBS may be caused by overgrowth of certain bacteria within the small intestine (American Journal of Gastroenterology, volume 95, 2000). The test for this condition is a hydrogen breath test.

To see our latest research article, click here
(pdf version)

What medications are used to treat IBS?

If there is evidence for bacterial overgrowth of the small intestine by the breath test, then we prescribe Xifaxan for 10-14 days followed by Zelnorm at bedtime for long-term use. We often give 2 treatments to help repair the damage and reduce permeability problems associated with the bacterial overgrowth: zinc and a probiotic containing bifidobacteria.

There are several classifications of medications that are prescribed for IBS. These medications work at different levels in the brain and body. Anti-cholinergic medications affect the vagal nerve and the vagal nerve endings on the muscles of the intestines. These medications are used to reduce the muscular activity of the intestines and are often the first line of medications to be prescribed. Anti-cholinergic medications can also be combined with a small amount of phenobarbital or Librium, which acts as a general anti-anxiety medication. When diarrhea and cramps are the primary symptoms anti-diarrhea medication such as Imodium and Lomotil are useful.

Anti-depressant medications are also used as therapy. IBS is generally treated with anti-depressant medications in doses much lower than those used to treat depression. Most commonly, antidepressants with anti-cholinergic activity such as amitriptyline, imipramine and deseryl can be helpful because they help relax the colon via anti-vagal nerve or anti-cholinergic properties and they act in the brain to alter the pain receptors and to reduce anxiety and improve insomnia. Comparing the two classes of antidepressants, tricyclics slow the transit and seratonin reuptake inhibitors such as Paxil and Prozac increase motility. In contrast to this type of drug therapy it is important to note that several medical studies have documented that psychotherapy and hypnotherapy are effective treatments for IBS.

New drug therapies for IBS include medications that work on the pain sensors on the surface of the intestine. A new medication called Zelnorm is designed to reduce pain and constipation. At end of this section state: If bacterial overgrowth exists, this can be treated with antibiotics and probiotics (a combination of good bacteria). Dicetel, a smooth muscle relaxant is available in Canada is a useful medication to treat IBS. Other drugs that affect other nerve receptors and another that block the action of cholecystokinin are being investigated. Fedotozine is being used in Europe and work on specific opioid pain receptors on the bowel but does not affect the intestinal motility or activity. This may be a good drug for the pain and possibly the bloating discomfort of IBS.

What anti-stress treatments are helpful to those who have IBS?

Stress management is one of the key treatments for many people with IBS. This can be accomplished in many ways ranging from exercise (especially walking and yoga), changing or getting away from stressful situations and practicing various relaxation therapies. For significant depression or a history of physical or sexual abuse consultation with a psychologist is recommended. The relaxation therapy that we recommend is a meditation process that can be taught to you by listening to a compact disc audio series (IBStherapy CDs). The relaxation gets down to your subconscious mind that helps guide your attitudes and reaction to stress on a continual basis.

There is no single therapy that works for everyone with IBS. The approach to treatment needs to be individualized and should be directed by a physician when the symptoms do not respond to basic changes in the diet.

Can IBS be cured?