Diarrhoea
People vary a lot in how often they open their bowels – usually between three times a day and three times a week. A stool should be solid, but moist and easy to pass.
In diarrhoea there is an increased frequency of bowel evacuation, as compared to normally bowel habits. The faeces passed are abnormally soft or watery.
Diarrhoea occurs due to changes in the cycle of fluid absorption and secretion across the intestinal wall between the bowel lining and the rest of the body. Movement of fluid, nutrients and chemicals across the intestinal wall can be by osmosis (fluids move from a less concentrated solution to a more concentrated solution) and active with chemical pathways, vitamins, bacteria and energy all being involved. The system is complex and the break down of any one part of it may lead to diarrhoea.
A few of the more common causes of loose, watery stools and abdominal cramps are infections from viruses, bacteria or parasites. Other causes include medications, particularly antibiotics and artificial sweeteners.
Chronic diarrhoea lasts much longer than acute diarrhoea. It can be a sign of a serious disorder, such as inflammatory bowel disease, or it may be due to a less serious condition, such as irritable bowel syndrome.
Abdominal cramps and pain
Cramping (spasmodic) abdominal pain is common with diarrhoea. When it is relieved by passing gas or stool, such pain is rarely cause for concern. After passing several loose stools, the abdominal muscles may feel sore, but this type of pain should stop after the diarrhoea stops. A young child with severe abdominal pain may clutch his stomach, scream, or pull his legs up to his chest
Frequent, loose, watery stools
Depending on the frequency of these stools, diarrhoea can be classed as mild, moderate or severe.
Mild diarrhoea: six to twelve moderately watery bowel movements; or four to six large, watery bowel movements in twenty four hours.
Moderate diarrhoea: eight to twelve moderately loose bowel movements in twenty four hours; or six to eight large, watery bowel movements in twenty four hours.
Severe diarrhoea: twelve or more moderately loose bowel movements in twenty four hours; or one large, watery bowel movement every hour for six hours or longer.
High temperature
High temperature (temperature over 38.5ºC or 101ºF) is a common symptom of diarrhoea caused by infection, by virus, bacteria or parasite.
Nausea and vomiting
Nausea and vomiting are also common symptoms when diarrhoea is caused by a viral infection.
Blood in stools
In an attack of diarrhoea caused by a bacterial infection, blood and mucous in the watery, loose stools is a possibility.
Food poisoning and infection
Diarrhoea is mainly caused by bacterial and viral infections and food poisoning.
Bacterial
Bacterial infections are the cause of food poisoning which typically occurs when poultry is undercooked or contaminated food is reheated insufficiently. Two commonly seen types of infection are Campylobacter and Salmonella.
In Salmonella symptoms may arise six to twenty four hours after eating the infected food. There is an abrupt onset of frequent diarrhoea, occasionally with abdominal pain and vomiting.
In Campylobacter infection there may be a longer incubation period (forty eight to seventy two hours) and abdominal pain is more common. Bloody diarrhoea may occur.
Bacillus cereus has an incubation period of one to six hours and is usually associated with boiled and fried rice, especially if it has been kept warm or reheated.
Viral
Viruses are often responsible for gastroenteritis (diarrhoea and vomiting). In infants the virus causing problems is one that also causes a cold and perhaps a cough. The infection starts abruptly and vomiting often occurs before diarrhoea. Although the worst symptoms may be over within two to three days diarrhoea may continue for some time afterwards.
Parasitic
Bowel infections are often acquired whilst travelling in countries where water and food sanitation is not as carefully controlled as our own (but are becoming more common in northern Europe, especially in nurseries and other institutions). Such infections can lead to dysentery, which is a disease involving the inflammation of the lining of the large intestines causing stomach pains and diarrhoea. The micro-organisms that cause such infections are protozoan parasites such as amoebas and giardia. Such infections may resolve themselves or may become chronic (long-term) and require treatment with antibiotics.
Medication
Many drugs have the side-effect of diarrhoea, but diarrhoea is most commonly caused by antibiotics and magnesium based indigestion remedies. Antibiotics cause diarrhoea by changing the natural intestinal bacterial environment. It is not an allergic reaction and antibiotics should not be stopped unless diarrhoea is severe and debilitating.
Food intolerances
Food intolerance can be defined as a condition where particular adverse effects occur after eating a particular food or food ingredient. The most common food intolerances are to lactose and gluten.
Lactose intolerance is relatively common and is due to a deficiency in the body of an enzyme, lactase that is needed to digest lactose before it can be absorbed. Lactase is released from the lining of the small intestine and breaks lactose down into two other sugars that the body can absorb easily. Lactase deficiency results in diarrhoea and other symptoms, such as bloating and abdominal pain. Many babies have cramping abdominal pain that makes them irritable (usually in the evening) for two to three months. This is colic and is often associated with diarrhoea. In some cases colic can also be due to an intolerance of lactose
Gluten intolerance is commonly known as coeliac disease. It is a digestive condition triggered by consumption of the protein gluten, which is found in bread, pasta, biscuits pizza crust and other foods containing wheat, barley or rye. Oats may contain gluten as well. When a person with coeliac disease eats foods containing gluten, an immune reaction occurs in the small intestine, resulting in damage to the surface of the small intestine and an inability to absorb certain nutrients from food. Symptoms of coeliac disease include diarrhoea as well as bloating and abdominal pain. Long-term undiagnosed coeliac disease may result in deficiency diseases due to long-term malabsorption of vitamins and minerals.
Anxiety
Anxiety, worries, excessive thinking and tension often cause stimulation of the vagal nerve (a nerve from the brain that sends signals to the stomach). This stimulation causes more acid secretion in the stomach which often causes diarrhoea.
Inflammatory bowel diseases
Such as Crohn’s disease and Ulcerative Colitis are chronic disorders of the gastrointestinal tract. They cause inflammation of the intestine, which results in abdominal cramping and persistent diarrhoea, which is often watery and bloody.
Bowel cancer
Along with other symptoms (some very similar to irritable bowel syndrome) a change in bowel habit, such as persistent diarrhoea or constipation may be a symptom of bowel cancer.
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is a chronic (long-term) condition affecting the small or large bowel. It causes pain or discomfort and an altered bowel habit and common symptoms can be abdominal cramps, bloating and diarrhoea.
Other disease states
Those conditions affecting hormone production (such as a thyroid condition) and diseases of the pancreas may result in diarrhoea.
Dehydration
The speed with which dehydration develops depends on the size of the individual, the frequency of the diarrhoea, and the presence of vomiting. Therefore, infants with frequent diarrhoea and vomiting are at risk, as are the elderly who are often dehydrated at the outset of the attack.
Signs of dehydration are:
- In children, sleepiness, drowsiness, irritability and unresponsiveness
- Marked thirst
- Infrequent urination or dark yellow urine
- Dry mouth or eyes that appear sunken
- Skin that has lost its normal elasticity
(To determine this, gently pinch the skin on the stomach using all five fingers. When you release it, it should spring back immediately; compare with another person’s skin if necessary. When the skin remains tented up and doesn’t spring back normally, the person may be dehydrated.)
Lack of absorption of medication and nutrients
In cases where causes of diarrhoea are not serious the lack of absorption of medication may only occur for as long as the diarrhoea occurs (possibly two to three days). This can still cause serious problems for those on the oral contraceptive pill (who may become pregnant as a result of the failure of even one pill to be absorbed into the bloodstream) and for those on medication to control epileptic seizures (where the lack or absorption of one to two days medication may result in a seizure). In diarrhoea lasting for some time that is caused by more serious diseases lack of absorption of most medication and nutrients will cause serious problems.
- If diarrhoea persists beyond one week.
- If you become dehydrated (see signs of dehydration above).
- If you have severe abdominal or rectal pain.
- If you have bloody or black stools.
- If you have a temperature of more than 38.5C or 101 F.
In young children, diarrhoea can quickly lead to dehydration. Contact your doctor if severe diarrhoea persists for more than twelve to twenty four hours or if your baby:
- Has not had a wet nappy for three or more hours.
- Has a temperature or more than 38.5C or 101 F.
- Has bloody or black stools.
- Has signs of dehydration (see signs above).
As well as addressing the abdominal pain and cramping and trying to control diarrhoea it is also very important to replace fluids and salts that have been lost through diarrhoea. Many over-the-counter preparations are not suitable for those who are pregnant or for children under two years of age and may not be suitable for other individuals, so it is always important to talk to your pharmacist when buying preparations for diarrhoea over-the-counter.
Oral rehydration therapy
The risks of dehydration from diarrhoea are greatest in babies and rehydration therapy is the only treatment recommended for children under twelve years. After this age anti-diarrhoeals can be used along with oral rehydration.
Sachets of powder for reconstitution are available in a variety of flavours; these contain essential salts required to re-balance the body’s natural balance of salts. They also contain glucose (a sugar) which helps the absorption of the salts in the bowel. These sachets should only be reconstituted with water (never fruit juice or fizzy drinks). It is also important that the exact quantity of water, as recommended by the manufacturer, is added to the sachet of powder, in order to produce the concentration of solution most suitable for the body. For babies under one year this water should be boiled and cooled.
The amount of rehydration solution drunk depends on the number of watery stools which are passed and the age of the person (please see below).
| Age | Quantity of solution (per watery stool) |
| Children up to one year | 50ml |
| One to five years | 100ml (half a glass) |
| Six to twelve years | 200ml (one glass) |
| Adults | 400ml (two glasses) |
Anti-diarrhoeals (e.g. loperamide)
This is effective in slowing diarrhoea and easing abdominal pain and cramps by reducing the contractions of the muscles in the bowel, however it may slow the elimination of the infectious agent, so avoid these products at least for the first six hours. When taking preparations containing anti-diarrhoeals, it is also important to take oral rehydration therapy to replace fluids lost whilst suffering from diarrhoea.
Arret
Imodium Instants both contain the anti-diarrhoeal loperamide. This is effective in slowing diarrhoea and easing abdominal pain and cramps by reducing the contractions of the muscles in the bowel. Imodium instants are designed to dissolve in the mouth and therefore eliminate the need to take water. It is extremely important to take large amounts of fluids when suffering from diarrhoea to replace those that have been lost and it is preferable for these to be in the form of rehydration salts (see below and above).
To stop diarrhoea with bloating and cramping
Imodium Plus contains the anti-diarrhoeal loperamide which is effective in slowing diarrhoea and easing abdominal pains and cramps by reducing the contractions of the muscles in the bowel. They also contain the surfactant simethicone, which helps to break down large bubbles of gas in the bowels to ease bloating and flatulence associated with diarrhoea.
To replace lose fluids in dehydration or to prevent dehydration
Dioralyte sachets contain sodium chloride 0.47g, Potassium chloride 0.3g, disodium hydrogen citrate 0.53g and glucose 3.56g.
Rehidrat sachets contain sodium chloride 0.44g, potassium chloride 0.38g, sodium bicarbonate 0.42g, glucose 4.12g and sucrose 8.1g.
The combination of electrolytes and sugar stimulates water and electrolyte absorption from the gut. It therefore prevents or reverses dehydration and replaces lost salts in diarrhoea. Each sachet should be dissolved in exactly 200ml water to obtain the concentration that suits the body best. They do not cause drowsiness.
There are several measures that can be taken to avoid getting diarrhoea:-
Wash hands
The spread of viral diarrhoea can be prevented by washing hands frequently and encouraging children to wash hands.
If you have diarrhoea stay away from others
Viral diarrhoea spreads easily so if you or your children are suffering from it, it is important to stay away from work or playschool/school. It is also important to stay away from those individuals who may become very ill if infected with the virus (babies, the elderly and those suffering from serious illness).
Avoid diarrhoea caused by contaminated foods
Use dairy products that have been pasteurized. Pasteurization involves heating dairy products for a period of time to kill bacteria.
Serve food immediately or refrigerate it after it has been cooked or reheated. Leaving food out at room temperature can encourage growth of bacteria.
Take common sense measures when travelling
Diarrhoea commonly affects people who travel to developing countries, where it is sometimes due to inadequate sanitation and contaminated food and water. To reduce your risks when travelling always drink bottled water, soft drinks or beer or wine served in its original container. If drinking hot drinks ensure water is completely boiled. When cleaning teeth use bottled water.
Avoid raw fruits and vegetables, unless they can be peeled and you peel them yourself. Avoid raw or undercooked meats, raw vegetables, dairy foods, tap water and ice cubes.
| Age of individual affected | Fluids | Food | General Hygiene |
| Baby under one year | Avoid dehydration. Increase frequency of breast/bottle feeds but give the baby half strength feed if you are bottle feeding. If the baby is vomiting your Dr may suggest that you stop milk feeding and only give clear fluids (normally oral rehydration salts). The amount of oral rehydration salts depends on the baby’s weight and degree of dehydration (and see guidelines above). | If your baby has started eating you may replace lost fluids with foods, such as cereal, strained bananas, or mashed potatoes after each diarrhoea stool. | Wash hands after changing nappies and dry with paper towels which should then be discarded. |
| Infants and Children over one year | Oral rehydration salts, half-strength juice or water may be used to replace lost fluids, depending on age offer half to one cup of fluid after each diarrhoea stool. If diarrhoea persists and/or infant/child becomes dehydrated use oral rehydration salts solely to replace lost fluids until stools return to normal. | If an infant/child is hungry do not withhold food. Give easily digestible foods such as rice, pasta, bread, carrots, mashed potatoes and bananas. Avoid foods and drinks high in sugar. | When changing nappies wash hands afterwards and dry on paper towels which should then be discarded. Ensure infants/children are washing hands after using the toilet and drying hands on paper towels which should then be discarded. |
| Adults | Aim to drink two cups of water or oral rehydration salts an hour unless you are vomiting. Avoid apple juice and milk as these can worsen diarrhoea. If diarrhoea persists or dehydration occurs use solely oral rehydration salts to replace lost fluids until stools return to normal. | Avoid solid food for a few hours until you feel better. | Wash hands after the toilet and before handling food. Dry hands with paper towels which should then be discarded. |