Laxatives are often used to relieve constipation, a common gastrointestinal complaint.
Some people need to move their bowels 2-3 times a day, while others go 2-3 times a week; there is no "normal" number of times. It is more important to notice changes to bowel habits.
Constipation is when stools become hard, making them difficult or painful to pass.
- Laxatives are commonly used to relieve constipation.
- Most are available without the need for any prescription.
- Some foods are known to have a laxative effect.
- Improving diet and increasing exercise can help reduce constipation, and therefore reduce the need for laxatives.
Constipation and how laxatives help
Constipation can cause cramps in the abdomen and can make people feel bloated or sick. It can be separated into two different types:
- Primary constipation - slow intestinal movements caused by an anatomical issue. This is often associated with not consuming enough fiber or not drinking enough fluids.
- Secondary constipation - associated with a metabolic disease (such as diabetes), neurologic diseases (stroke, Parkinson's disease, multiple sclerosis), connective tissue disorders, or eating disorders.
Some medications can also contribute to constipation; these include antidepressants, iron, bismuth, anticholinergics, opioids, antacids, calcium channel blockers, nonsteroidal anti-inflammatory drugs (NSAIDs), sympathomimetics, and antipsychotics.
Types of laxatives
Different types of laxatives work in different ways. The choice of laxative will depend on a number of different factors.
There are four main types:
- Bulk-forming laxatives - also known as fiber supplements, these work in the same way that fiber in the diet normally does. They increase the bulk of stools by getting them to retain liquid, which encourages the bowels to push them out. Unless there is a specific reason why not, adults with constipation should start taking bulk-forming laxatives first. They usually take 12-24 hours to take effect.
- Osmotic laxatives - these soften the stool by increasing the amount of water secreted into the bowels, making them easier to pass. They may take up to 2-3 days before they start to work.
- Stimulant laxatives - these stimulate the digestive tract walls, speeding up bowel movements. Usually, they take effect within 6-12 hours.
- Stool softener laxatives - these decrease the surface tension of stools so that they absorb more water, making them softer. Usually, they work within 12-72 hours.
There are also some less common types of laxatives:
- Lubricant laxatives - these lubricate the intestines by decreasing the amount of water absorbed by the intestines.
- Saline laxatives - these are used when there is no blockage in the bowels. Often, they are enemas used to empty the bowel before invasive procedures or surgery.
- Prokinetic laxatives - these are used for severe constipation in conditions such as irritable bowel syndrome (IBS) and chronic idiopathic constipation.
Negative side effects include bloating, feeling sick, and abdominal discomfort.
Like any medication, laxatives can have side effects. Exactly what side effects a person will experience will depend on what type they are taking.
There are some common side effects, which include:
- cramps in the abdomen
- feeling sick
- dehydration - can cause light-headedness, headaches, and darker urine
Most side effects will disappear once a patient stops taking the medication; they can mostly be avoided by starting on a low dose and increasing the dose gradually.
Serious side effects are rare. However, excessive or prolonged use of laxatives can cause diarrhea or intestinal obstruction, where stools become large and dry. Long-term use can also cause levels of salts and minerals in the body to become unbalanced.
Some laxatives react with other medications, so if a patient is taking other drugs, it is best to check with a doctor before taking laxatives.
If symptoms get worse after taking laxatives, it is important to see a doctor.
Misuse of laxatives
Laxatives can be taken for the wrong reasons and misuse is relatively common; for instance, some people attempt to lose weight by the frequent and repeated use of laxatives.
Often, this occurs after eating binges under the mistaken belief that food and calories will be rushed through the body before they are absorbed. This is not the case, and laxative abuse can lead to a number of health complications.
While those misusing laxatives may notice weight loss, this is usually because of the loss of fluids; they do not reduce body mass, fat, or calories.
Health complications associated with laxative misuse include:
- Imbalance of electrolytes and minerals (particularly potassium) - these are necessary for the proper functioning of nerves and muscles, including the colon and heart. Imbalance can affect these organs.
- Severe dehydration - this can cause tremors, weakness, blurry vision, and kidney damage. In extreme cases, it can lead to death.
- Laxative dependency - the colon stops reacting to usual doses, meaning larger and larger doses are required.
- Internal organ damage - the colon can become stretched and the muscle wall becomes thin and flaccid.
Colon infection, IBS, and liver damage are also associated with overuse. Chronic laxative misuse can also contribute to colon cancer.
Laxative misuse often requires medical help for both physical and mental treatment. A doctor will be able to give advice on this. However, here are some basic tips for giving up laxatives:
- eat plenty of fruit and vegetables, foods high fiber, and wholemeal foods
- drink plenty of water
- avoid large quantities of bran
Safely using laxatives
How someone takes laxatives, and how often they take them, will vary depending on the form they come in.
Therefore, it is important to carefully read the instructions before taking laxatives. Anyone with concerns should always ask a pharmacist or healthcare professional.
There are also some other important things to consider:
- Drink plenty of fluids - laxatives can cause dehydration; it is important to drink at least 2 liters of water a day.
- Avoid taking too much - taking too many laxatives can lead to diarrhea and blockages in the bowels.
There are some natural alternatives to laxatives and lifestyle changes that can help alleviate constipation:
- regular exercise
- increasing daily intake of fiber
- drinking more water
- adding bulking agents, such as bran, to diet