Conditions

Irritable bowel syndrome (IBS) or spastic colon is one of the most common gastrointestinal disorders.

Summary

  • The cause of irritable bowel syndrome is unknown.
  • It is the most common disorder of the intestines.
  • It can lead to the formation of diverticula, especially if the diet is low in fibre.
  • It does not affect life expectancy.
  • It is characterised by abdominal pain, bloating and irregular bowel movements.

Description

Irritable bowel syndrome (IBS) or spastic colon is one of the most common gastrointestinal disorders. It has also been called spastic colitis, mucus colitis or nervous colon syndrome. It tends to be a chronic disorder, and the symptoms can wax and wane over many years. Most people have such mild symptoms that they never seek medical help.

The disease is a functional bowel disorder involving the large intestine. Common symptoms are abdominal pain, bloating, mucus in stools, and irregular bowel habits, such as alternating diarrhoea and constipation. The symptoms are related to abnormal muscle contractions in any part of the intestines. A spastic colon does not adversely affect longevity or lead to more serious diseases such as inflammatory bowel disease or cancer.

The symptoms of a spastic colon typically occur early in life and half of those affected experience the symptoms before they reach the age of 30.

Cause

There is no known cause of spastic colon. Most symptoms are related to abnormal muscle movement or spasm of the lower part of the colon. Sometimes the spasm delays the bowel movement, resulting in constipation, and sometimes it may lead to more rapid passage of the bowel movement, resulting in diarrhoea. Dietary, psychological, hormonal or genetic factors may play a role.

The following may bring on some of the symptoms:

  • Stress, anxiety and depression
  • Smoking
  • Food sensitivity, especially as people age
  • Overeating, binge eating, eating irregularly or too quickly
  • Too much fat in the diet
  • Lactose intolerance
  • Sugar substitutes such as sorbitol and aspartame
  • Certain antibiotics that alter the population of bacteria in the intestines
  • Morphine and codeine
  • Aluminium salts of antacids
  • The prescription drug methotrexate
  • Tricyclic antidepressants
  • Certain antihistamines, mineral supplements, diuretics, antipsychotics and sedatives
  • Sensitivity to intestinal sensations (visceral hyperalgesia)
  • Hormonal changes, for example during the menstrual cycle

Symptoms

  • Symptoms vary from person to person and in one individual both constipation and diarrhoea can occur and either can recur.
  • Symptoms usually start during adolescence or early adulthood.
  • Symptoms appear over periods of days to weeks.
  • Constipation or diarrhoea develops shortly after meals, over a period of several weeks.
  • Abdominal pain and/or cramping occur. The pain can vary from mild to severe. It is usually felt in the lower abdomen, especially on the left side. The pain may be dull or sharp, and continuous or felt as cramps. Pain is relieved by passing wind or by defecation. It does not occur at night.
  • There may be a bloated feeling, abdominal distension, increased intestinal gas (flatulence) and belching.
  • Bowel movements differ in frequency or consistency from a person's normal pattern. During constipation, stools may be hard, small, pellet-like, and difficult to pass. A sense of incomplete evacuation may follow. Passage of the stool may relieve the pain. The diarrhoea of a spastic colon is usually of small volume, but frequent. Episodes usually occur during times of stress. The first movement may be normal, but followed by loose bowel movements throughout the rest of the day. Bowel movements may be associated with extreme urgency and can be explosive.
  • Mucus may be passed in the stools.
  • On rare occasions, heartburn, nausea and vomiting occur.
  • Loss of appetite may occur.
  • Some women have painful menstrual periods, and pain during intercourse.
  • Symptoms rarely if ever occur at night and do not normally wake the person from sleep.

Prevalence

Up to 15% of the American population has IBS, although only about 20% of this group seek medical attention. Only a small percentage has chronic symptoms. Much the same is found in South Africa.

Course

Although the symptoms may persist for a long time, the disorder does not cause cancer and does not shorten a person's life expectancy. In some people, especially those with a low-fibre diet, it may lead to diverticulosis of the colon, an inflammation of one of the pouches (diverticula) occurring in the mucous lining of the large intestine.

Some people experience symptoms intermittently for many years. Sometimes months go by without any symptoms. Most people have recurrent episodes of symptoms but the symptoms tend to get better over time. People seldom have constant symptoms.

Risk factors

Spastic colon tends to be more common in the following people:

  • People younger than 35 – if symptoms occur for the first time after this age, a diagnosis of spastic colon becomes unlikely.
  • People with panic disorder.
  • People who have a family history of IBS.
  • People who have a history of physical or sexual abuse or other psychological trauma.

When to see a doctor

  • If you have been diagnosed with spastic colon and your symptoms get worse, begin to disrupt your activities, or do not respond to your home treatment.
  • If you become increasingly fatigued.
  • If your symptoms wake you frequently.
  • If you been losing weight unexpectedly.
  • If you have a diminished appetite.
  • If you have abdominal pain that is not associated with changes in bowel function or that is not relieved when you pass wind or a stool.
  • If you have a fever.
  • If there is mucus in your stools.
  • If there is blood in your stools.
  • If you have not been diagnosed with spastic colon but have the symptoms, and you have ruled out other possible causes and tried home treatment without any success.

Diagnosis

There is no specific test to diagnose a spastic colon, but a number of tests may be done to rule out other conditions. Such conditions include food allergies, intestinal infections, parasites, diverticular diseases, colon cancer and Crohn's disease, an inflammation usually affecting the ileum (lower part of the small intestine) and occasionally other parts of the digestive tract.

The amount of testing will depend on several factors: your age, how the symptoms present themselves, how severe the symptoms are, and how you respond to the initial treatment.

Initially the doctor will take a history and do a physical examination. The doctor will want to know:

  • If the symptoms have occurred continuously or have been recurring for three months or longer.
  • If the abdominal pain or discomfort is relieved by passing stools or is associated with a change in the frequency or consistency of the stool.
  • If two or more of the following are present on at least 25% of occasions or days:
    • Changed stool frequency and form (lumpy/hard or loose/watery).
    • Changed stool passage (straining, urgency or feeling of incomplete evacuation).
    • Mucus in the stool.
    • Bloating or a distended abdomen.

Tests may be done on blood and stools to exclude infections, parasites, and anaemia, thyroid and other hormone disorders.

A barium enema X-ray may be ordered. This involves administering a chalky substance (barium) through the rectum into the colon, making it possible to take X-ray photographs of the large intestines. Abnormal contractions of the intestines will be recognisable on these X-ray films and diverticulosis, colon cancer and colon obstruction can be detected.

A flexible viewing tube (sigmoidoscope or colonoscope) may be inserted into the rectum to directly view the inner rectal lining and the colon. This procedure can reveal increased contractions of the intestine and may rule out other conditions such as cancer, major polyps or infections.

Treatment

As spastic colon does not have a specific underlying cause, treatment is intended to relieve the symptoms.

Home

Certain foods may contribute to a spastic colon by irritating your gastrointestinal tract. Your health professional will help you to assess the quality of your diet and then recommend a balanced nutritional programme.

You may be told to cut your consumption of dietary fat, whether it is vegetable oil or animal fat, saturated or unsaturated. Other known irritants are eggs and dairy products, spicy foods and coffee. An elimination diet may help you discover food sensitivities. Do not eat a suspected food for 10 to 30 days. Then try it again and if you get an adverse reaction, avoid that food in future.

It may be a good idea to keep a diet diary to determine if a particular food makes your symptoms worse.

Most people do not eat enough fibre. Therefore, it may be recommended that you:

  • Gradually increase the amount of fresh fruits and vegetables, whole grains and bran in your diet.
  • Take one tablespoon of bran stirred into a glass of fruit juice or water every day.
  • Take one tablespoon of soluble fibre in a glass of cold water or juice once a day.

Increase your water intake if you take supplementary fibre. At first the amount of intestinal gas may increase, but it should subside as your body adjusts.

Your doctor may also recommend that you eat smaller meals more often or eat smaller portions of foods during meals.

Relaxation and biofeedback techniques may help you manage stress. Drink eight glasses of water a day. Do not drink alcohol.

Medication

After more serious conditions have been ruled out, the doctor may prescribe a bulk-forming, soluble fibre dietary product such as methylcellulose or psyllium (Plantago psyllium) to help regulate bowel movements and ease the problems of both diarrhoea and constipation.

If this is not effective, your doctor may prescribe loperamide to slow the movement of food through the intestines, or hyoscyamine, chlordiazepoxide, phenobarbitone or dicyclomine to calm the gastrointestinal tract and to relieve cramps.

Antidiarrhoeals or laxatives can be used for short periods when the symptoms of diarrhoea or constipation are severe.

If you are depressed or under excessive strain, your doctor may prescribe tranquillisers or antidepressants such as amitriptyline. Tricyclic agents or selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine or paroxetine could be prescribed for those with severe, chronic symptoms. These antidepressants not only affect mental activity, but also ease the pain and dampen the activity of the neurons that control actions in the gut.

Other

Many people believe that a spastic colon is an imaginary illness, but a doctor could reassure you that this is not the case. If you are under stress and/or depressed, ask your doctor to refer you to a clinical psychologist. Counselling or psychotherapy may help relieve concerns that are aggravating your condition.

Prevention

  • Make sure that there is enough fibre in your diet – about 30g daily.
  • Do not smoke.
  • Avoid excessive amounts of caffeine, for example in coffee, colas and chocolate.
  • Get regular exercise to help regulate bowel movements.
  • Participate in healthy activities to reduce stress.

(Reviewed by Prof Don du Toit)

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