What is irritable bowel syndrome?

Irritable bowel syndrome (IBS) is a condition that affects the digestive system. It often appears between the ages of 20-30 years and affects women more than men. The symptoms are usually bouts of painful stomach cramps,  diarrhoea, bloating and constipation. If you have been diagnosed with IBS, you may experience constant symptoms, or you may only have a few flare-ups per year. It is a very unpredictable condition, which is not life-threatening.                                                                                                                                                                                                  

Digestive system

The series of organs within the body that contribute to the digestion of food. It begins at the mouth and ends at the anus, and includes the stomach, small and large intestines as well as the pancreas, gallbladder and liver.

Causes

While there is currently no known reason for developing IBS, specialists in the field, called gastroenterologists, believe it is caused by several different factors.

Normally, food moves through your digestive system in a slow, rhythmic way, the squeezing and relaxing of intestinal muscles (peristalsis) gently pushing it along. In IBS, this movement changes, either becoming too fast or too slow and creating discomfort. If the food moves too slowly, you get constipation, as too much water gets absorbed by your body. If the food moves too quickly, not enough water will be absorbed, giving you diarrhoea.

Stress, previous food-related illness and certain food types seem to trigger flare-ups of IBS. Other potential causes may be:                                                                                   

Increased gut sensitivity

There are many nerve receptors in your digestive system that tell your brain if you are full, in pain or need to go to the toilet. There is thought to be a link between IBS and a change in how these nerves work. Serotonin, a chemical produced in your gut, may be overproduced or underproduced in IBS. This may explain the increased sensitivity to abdominal pain and bowel movements.

Emotional factors

It is considered normal for emotional stress to cause changes in bowel movements; both diarrhoea and constipation are common side effects to stress in our lives. Our bodies constantly send signals back and forward between our bowels and our brains. During stress, these signals increase, causing more intestinal contractions and sensitivity. This appears to occur in IBS.

Diet

Certain foods appear to trigger flare-ups of IBS, such as:

  • Drinks containing caffeine, such as cola, tea or coffee;
  • Fizzy, carbonated drinks and alcohol;
  • 'Gassy' foods, such as beans or cabbage;
  • Non-soluble fibre foods, such as nuts and seeds;
  • Fried, fatty or spicy foods;
  • Highly-processed snacks, such as crisps, chocolate and biscuits, and;
  • Foods containing lactose (milk sugar) or fructose (fruit sugar).

Digestive system infection

Quite often you may experience ongoing bowel symptoms long after you have recovered from an episode of food poisoning or gastroenteritis. The bacteria in our bowels may be affected in the long-term by digestive system infections, causing abnormal bowel symptoms well into the future.

Medications

Some medications can give you diarrhoea or constipation, which may trigger IBS attacks. Pain-relief medications, antacids and antibiotics are all known to have this effect.

Antacids

A substance that neutralises stomach acidity, often used to treat heartburn.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Digestive system

The series of organs within the body that contribute to the digestion of food. It begins at the mouth and ends at the anus, and includes the stomach, small and large intestines as well as the pancreas, gallbladder and liver.

Fructose

A type of sugar found in honey and sweet fruits.

Nerve

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Serotonin

A chemical messenger within the brain that is thought to play a role in mood and behaviour. Many antidepressant medications act by increasing the amount of serotonin in the brain.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

Abdominal

Relating to the abdomen, the middle portion of the trunk which contains organs such as the intestines, stomach and liver.

Types

There are three main types of irritable bowel syndrome:

Diarrhoea predominant IBS

This type of IBS normally alternates between  diarrhoea and normal bowel movements. Diarrhoea often occurs first thing in the morning or just after food. The urge to go to the bathroom is often immediate and very urgent, which can lead to embarrassing incontinence incidents.

Constipation predominant IBS

This is when you mainly experience constipation together with painful cramps in the abdomen, often just after eating.

Alternating IBS

This is when you experience both constipation and diarrhoea, often having normal bowel movements in between attacks.

Abdomen

The part of the body that lies between the chest and the pelvis.

Incontinence

The uncontrollable loss, small or large, of bladder or bowel control, resulting in leakage of their contents.

Risk factors

Risk factors for IBS include:

Antacids

A substance that neutralises stomach acidity, often used to treat heartburn.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Signs and symptoms

IBS symptoms tend to come and go, often getting worse after you have eaten. Passing wind or going to the toilet often relieves the pain. The severity of symptoms can vary between people, depending on the type of IBS you have been diagnosed with. Flare-ups tend to last for between 2-4 days, often after a time of change or stress in your life, then gradually improve. Bowel movements can change between hard, pellet-like stools to explosive, urgent diarrhoea. Some women find their symptoms get worse around their menstrual cycle. Other common IBS symptoms include:

  • Indigestion, often with loud grumbling stomach sounds and bloating;
  • Wanting to empty your bowels, even though you have just been to the toilet;
  • Tiredness and backache;
  • Alternating diarrhoea or constipation, often with mucus present;
  • Flatulence (wind), and;
  • Nausea or lack of appetite.

 

Stomach cramps, indigestion, bloating.Irritable bowel syndrome can cause indigestion and bloating of the abdomen. 

Abdomen

The part of the body that lies between the chest and the pelvis.

Indigestion

Stomach pain or discomfort caused by difficulties digesting food.

Menstrual cycle

A monthly cycle of changes that a woman's body goes through to prepare for a potential pregnancy.

Mucus

A thick, viscous liquid that is secreted for lubrication and to form a protective lining over certain tissues.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

Methods for diagnosis

There are several other conditions that have similar symptoms to IBS, such as coeliac disease, Crohn's disease, diverticulitis and intolerances to lactose and fructose. Your doctor may want to discuss your symptoms in detail, to make sure you do not have one of these other bowel conditions. There is no single test for IBS, but the following tests may be suggested:

Physical examination

Your doctor may check for any abnormalities in your abdomen or rectum.

Blood tests

There is no blood test that diagnoses IBS, but it is important to exclude other conditions. Therefore, blood tests can check for antibodies, iron levels and signs of other bowel conditions. 

Colonoscopy

A colonoscopy is used to examine the entire length of the bowel. Before the procedure, the bowel may need to be cleansed using an oral laxative solution or an enema. You may also be asked to not eat, but to drink plenty of clear fluids in the 12-24 hours prior to the procedure. During the colonoscopy a thin, flexible tube with a camera is passed through the bowel, via the anus. Air is usually pumped through the bowel to allow your doctor to properly view the inside lining for abnormal lesions.

There are usually no specific findings on colonoscopy to help diagnose IBS. It is mainly performed to exclude other serious conditions that may mimic IBS. 

Your doctor may suggest a colonoscopy to help investigate IBS. 

Stool test

A stool test can check for any abnormal bacteria in your stools. This involves collecting a small sample of your stool in a special container, which is sent away for testing, avoiding any embarrassment. Stool tests can also assess for mucus and blood, which may be present in conditions that can mimic IBS. 

Abdomen

The part of the body that lies between the chest and the pelvis.

Antibodies

A protein molecule produced by the immune system. Antibodies bind specifically to foreign substances to neutralise them or target them for destruction.

Anus

The opening at the end of the anal canal, between the buttocks, through which faecal matter and intestinal gas exits the body.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Enema

A procedure in which fluid or gas is injected into the rectum for cleansing, diagnostic or therapeutic purposes.

Fructose

A type of sugar found in honey and sweet fruits.

Iron

An essential mineral required by the body. Iron is part of a protein in the blood called haemoglobin, which carries oxygen around the body.

Mucus

A thick, viscous liquid that is secreted for lubrication and to form a protective lining over certain tissues.

Rectum

The final part of the large intestine, leading to the anus.

Lesions

A localised abnormality in a bodily tissue, usually caused by injury or disease.

Types of treatment

There is no known cure for IBS, so the focus of treatment is to avoid triggering for your symptoms.

Diet

There are many dietary measures you can take to control IBS, including the following: 

  • Keep a food diary. This will help you discover which foods trigger your flare-ups. You may not need to avoid them for life, but discussing your situation with a dietitian will help you find an eating plan to suit your type of IBS;
  • If you have constipation, drink more water and try eating more foods with fibre, such as barley, oats, bananas, apples and carrots;  
  • If you have diarrhoea, eat more foods such as wholegrain bread and cereals, but avoid eating fruit peels, piths and seeds;
  • Drink lots of water, but lower the amount of fizzy drinks and alcohol you consume;
  • Reduce your intake of tea and coffee;
  • If you have diarrhoea, avoid the sweetener sorbitol, which is found in many sugar-free sweets and chewing gum, and;
  • Eat regular small meals.

Stress

Stress and anxiety appear to play a big role in triggering IBS symptoms. Finding ways to relax and reduce your stress levels may help lessen the severity and number of flare-ups. Relaxation techniques, such as deep breathing, meditation or practising yoga, may help.

Exercise 

Exercise may help with many of the symptoms of IBS, potentially by reducing anxiety and relaxing you. Your doctor will help advise you on what will suit you best. Taking a regular walk, swimming, running, and gentle exercises such as tai chi, may all help reduce symptoms.

Medications

There are a range of medications that can help you control your symptoms of IBS, including: 

  • Diarrhoea medications - antimotility medications can reduce diarrhoea by slowing down your intestinal movement (peristalsis). These are useful for socially embarrassing diarrhoea. Always speak to your doctor before taking any medication to stop diarrhoea;
  • Pain-relief medications, such as paracetamol;
  • Antidepressants - your doctor may suggest trialling certain antidepressants, as they can help with pain relief in some cases of IBS, and;
  • Antispasmodic medications may help relieve painful stomach cramps.

Antidepressants

Medication used to treat depression and other mood disorders.

Anxiety

A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

Sorbitol

A sweet-tasting compound that may be used as a substitute for cane sugar, as it is absorbed more slowly.

Potential complications

IBS is not a life-threatening condition, but it can have a serious impact on your lifestyle and ability to work. The discomfort and embarrassment of the symptoms can lead to anxiety and depression.

Anxiety

A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.

Prognosis

If you have IBS, you will have to manage your symptoms for the rest of your life. You may experience disabling symptoms on a daily basis, or you may be relatively symptom-free; each case is different. While there are no particular medicines that can cure IBS, some medications can help with managing symptoms. Identifying what causes your flare-ups is key to this.

Prevention

If you have had an infectious bowel condition, or food poisoning, ask your doctor for advice on keeping your bowels healthy. Consider taking a probiotic supplement to maintain the healthy bacteria that are usually present in your bowel. Try to follow a healthy diet and avoid foods that upset your bowels, such as drinking too many caffeinated drinks. Also, exercise regularly and make time to relax each day. 

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Probiotic

Bacteria that have health benefits to the human body, such as Lactobacillus bacteria, which is added to yoghurt to improve digestion.