In this article:
- Certain dietary and lifestyle modifications may help to relieve primary constipation.
- Antibiotics rarely cause constipation as a side effect. However, they may disrupt the gut flora, which leads to gas and diarrhea.
- There are some other medications which may cause constipation. These include blood-pressure drugs, anticholinergics, opioids, antispasmodics, antacids, etc.
What Is Constipation?
It can be defined by having any two of the following characteristics (at least 25% of the time):
- Straining during bowel movements (BMs)
- Hard bowel movements
- Incomplete evacuations
- Sensation of obstruction or blockage
- Fewer than three bowel movements per week
This definition comes from a panel of experts and is referred to as the Rome IV criteria. (3)
Primary Vs. Secondary Constipation
Primary constipation is usually a symptom of functional issues listed in the next section. Secondary constipation is due to medications or an underlying disease.
The small intestine absorbs nutrients from digested food and passes the remaining material into the colon. The colon absorbs water from this waste material and helps to reabsorb the water back into the system. The waste material is further passed on to the rectum for a bowel movement to occur.
Constipation may occur when the stool becomes dry or hard due to excessive water absorption by the colon. This creates difficulty in passing the stool.
Usually, the frequency of bowel movement varies from three times a day to three times a week. Fewer bowel movements than your routine may suggest constipation.
Constipation may be accompanied by several other signs and symptoms including:
- Blood with bowel movement
- Rectal pain
- Bad odor due to flatulence
- Need to apply excessive pressure while having a bowel movement
- A feeling of an incomplete bowel movement
- Bloating in the abdominal region
- Loss of appetite
Primary Constipation (Functional Causes)
Constipation can occur due to a change in your lifestyle. Common reasons for constipation include the following:
- Nutritional (vitamin and mineral) deficiency
- Lack of fiber in the diet
- Poor hydration
- Sleep deprivation
- Lack of exercise
- Anxiety or emotional turmoil
- Old age
- Gender – females more likely to have constipation than males
- High intake of certain foods such as dairy products and iron supplements
Constipation can also occur as a symptom of certain diseases, and this is called secondary constipation.
Inflammatory diseases, infectious diseases of the bowel, and irritable bowel syndrome are common causes of secondary constipation.
Neurologic disorders, metabolic disorders, and endocrine disorders such as diabetes all have an increased incidence of constipation.
If your constipation is accompanied by pain, weight loss, or bloody stools or it does not resolve after 1-2 weeks, seek medical advice.
What Are Antibiotics?
Antibiotics are a class of drugs that kill bacteria or curb their growth.
These chemicals target the parts of bacteria involved in their growth and survival. For example, an antibiotic may work by inhibiting the formation of the bacterial cell wall and formation of proteins or by altering the bacterial cell membrane.
The inability of the bacteria to grow in the presence of a particular antibiotic indicates their susceptibility to that antibiotic.
Some antibiotics arrest the growth of bacteria (bacteriostatic), and other antibiotics directly kill the bacteria (bactericidal).
Antibiotics are highly useful in managing infections caused by bacteria. They can be broadly classified into two categories:
- Broad-spectrum antibiotics: These antibiotics target a wide variety of bacteria at once. They may also affect those bacteria that are beneficial to our health.
- Narrow-spectrum antibiotics: These antibiotics attack only some bacterial species and are highly specialized.
Do Antibiotics Cause Constipation?
Broad-spectrum antibiotics that are used to kill pathogenic bacteria can also affect the commensal bacteria living in our gut. This disturbs the composition of the gut flora. As a result of the imbalance, you may suffer from gas and diarrhea.
Therefore, antibiotics commonly cause diarrhea as a side effect. They may rarely cause constipation.
Other side effects of antibiotics that affect the digestive system include:
- Nausea and vomiting
- Lack of appetite
- Improper digestion
- Abdominal bloating
Medications That Can Cause Constipation
Constipation can result from many reasons. It is often a side effect of certain medicinal drugs, which include:
Calcium-channel blockers: Diltiazem (Cardizem) and amlodipine (Norvasc) are examples. These drugs are used to lower blood pressure by relaxing the smooth muscles of blood vessels.
They may also relax the gut muscles, thus causing constipation.
Anticholinergics: Anticholinergics are used to treat a variety of conditions including:
- Urinary incontinence (loss of bladder control): oxybutynin (Ditropan)
- Allergies: diphenhydramine (Benadryl)
- Depression: antidepressants
Acetylcholine, a neurotransmitter responsible for inducing muscle movement, is blocked by anticholinergics. Loss of movement of the intestinal muscles due to the ineffectiveness of acetylcholine can cause constipation. (4)
Opioids: Opioids are used for pain relief and include morphine and codeine. Also known as narcotics, these drugs bind to pain receptors and prevent the dispersion of pain signals.
These drugs can stimulate an increase in the absorption of water by the colon, causing constipation.
Antispasmodics: Antispasmodics, such as dicyclomine, are used to suppress muscle spasms. These medicines work by reducing the frequency of muscle contractions.
Reduced muscle contractility may affect the peristaltic movement of waste material in the colon and induce constipation.
Antacids: Antacids contain aluminum, which affects the muscular activity of the gut, resulting in constipation.
Cholestyramine: Cholestyramineis used to reduce cholesterol levels in the blood. By binding to bile acids, it affects water absorption from the food. As a result, the stool formed is dry and hard to pass.
Consult your clinical practitioner before using any of these medications.
Researches that Support the Relation Between Medications and Constipation
Several studies have suggested that some medications can cause constipation:
- The association of constipation with the increasing number of drugs used by the elderly was demonstrated in a population-based study conducted in 2018. (5)
- A 2003 study, published in the Journal of Neurology, Neurosurgery, and Psychiatry, reviewed the incidence of constipation in patients with neurological diseases. Findings indicated that a variety of drugs could alone, or in combination, cause or worsen constipation. (6)
- A case study in 2005 reported gastrointestinal complications in two patients taking antidepressant drugs. The patients showed symptoms associated with the action of anticholinergic medicines, including dryness in the mouth, blurred vision, tremors, and constipation. (7)
- A meta-analysis conducted in 2011 found that patients taking anticholinergics for an overactive bladder were prone to constipation. (8)
- A review study in 2016 found constipation to be one of the most frequent adverse side effects of anticholinergics in the elderly. (9)
- Constipation was found to be commonly associated with prolonged use of opioids, according to a study conducted in 2016. (10)
Individuals at High Risk of Constipation
- Older adults are more susceptible to constipation, which occurs as a side effect of medications. This is primarily due to the decreased motility with aging.
- Infants become highly susceptible to constipation if they are given poor-quality milk.
- Constipation may also occur in people with a lack or imbalance of beneficial gut bacteria, a condition medically known as dysbacteriosis.
- Pregnant women are at a high risk of constipation primarily due to their high levels of progesterone. The use of certain medications by pregnant women can exacerbate this.
How to Restore Natural Bowel Movement
Constipation can be resolved by making a few changes in your lifestyle, including:
- Exercising regularly with an aerobic type of exercise such as walking
- Consuming fiber-rich foods such as fruits, vegetables, and grain products such as bran
- Drinking more water
- Consuming natural yogurt or probiotic drinks to restore gut flora
You can also take the help of over-the-counter laxatives or stool softeners.
If the condition persists, visit your doctor.
Complications of Constipation
Constipation occurring as a side effect of medications can lead to health complications:
- Hemorrhoids may develop from straining too much with bowel movements.
- Straining due to constipation may lead to a tear in the anus, called an anal fissure, with associated bleeding.
- A large lump of stool may develop and stay stuck in the rectum. This is known as fecal impaction.
- Intestinal obstruction.
- A blockage in the colon can form, behind which buildup of gas, gastric acids, fluids, and food can take place. The buildup can create excessive pressure, which can rupture the intestine.
- Constant straining during a bowel movement can lead to arrhythmia or an irregular heartbeat.
Constipation is a very common problem. It is usually a side effect of medications and can be easily managed through self-care. If the problem does not subside, seek medical help.
Chronic constipation can give rise to complications that are difficult to treat. Although antibiotics occasionally are associated with constipation, some of the more common side effects associated with antibiotics seem to be diarrhea and gas.
Expert Answers (Q&A)
Answered by Dr. Rajan Menghani, DO
Antibiotics can have a wide variety of side effects, ranging from a skin rash, nausea, and upset stomach to worse issues such as hearing loss.
In rare cases, life-threatening conditions such as Stevens-Johnson syndrome (which may cause a fever and a skin rash with blisters) can result.
Ask your doctor about the side effects that you may expect when taking antibiotics, and make sure to notify your doctor if they become bothersome.
If you experience wheezing, difficulty breathing, or swelling in your tongue, lips, or throat, then seek medical attention or call 911 immediately as these symptoms may indicate a life-threatening allergic reaction called anaphylaxis.
It is also important to note that taking unnecessary antibiotics can increase the risk of bacteria becoming resistant to it. This means that the next time this same antibiotic is given to you, it may not be effective and another antibiotic may be necessary.
Therefore, only take antibiotics that are prescribed by your doctor, and do not self-medicate with antibiotics just because they are sitting in your medicine cabinet.
A variety of drugs may cause constipation, but some of the most common culprits are opioid medicines, which are sometimes prescribed for severe pain.
Some antibiotics may affect how oral contraceptives are metabolized in the body. They can decrease the efficacy of contraceptives and may increase your risk of becoming pregnant if you are sexually active.
It is therefore necessary to let your doctors know of all contraceptives, medications, and supplements you are taking so that they may make the right decision and give you the necessary instructions.
Some people, especially children, may be sensitive to dairy products and may develop constipation after consuming them. A study done in Spain showed that drinking cow’s milk may cause constipation in children. (11) However, because everyone is different, not everyone will have the same reaction to a specific food.
If you do develop constipation while on a certain antibiotic, your doctor may recommend a different antibiotic or may advise you to include adequate fiber and water in your diet.
Several antibiotics are considered safe for children. However, there are some notable exceptions, including tetracyclines and fluoroquinolones.
Tetracyclines (such as doxycycline and tetracycline) should not be given to children under 8 years old because they can cause permanent discoloration of the teeth. It is best to avoid giving fluoroquinolones (such as ciprofloxacin and levofloxacin) to anyone under the age of 18 years because they can cause tendinitis or rupture of the tendons.
Make sure you address all of your concerns with your doctors and work with them to determine which antibiotics, if necessary, are right for you.
When you visit your doctor, be prepared to answer questions regarding health issues you have had, allergies, and medicines and supplements you are taking.
Also, inform your doctor if you may be pregnant, as some antibiotics may potentially harm the baby. Your doctor may then want to perform a pregnancy test. This information is essential for the doctor to determine which antibiotic, if necessary, is right for you.
It is important to take antibiotics exactly as prescribed and finish the entire course so that the infection is properly treated and the bacteria do not survive and become resistant to the antibiotic.
About Dr. Rajan Menghani, DO: Dr. Menghani is a family physician who pays special attention to preventive medicine. When taking care of his patients, he puts emphasis on exercise, dietary modifications, and sleep hygiene, among other measures. He also has a special interest in public health, nutrition, and research.
Dr. Menghani graduated with a bachelor’s degree in psychology from UCLA and earned his doctorate in osteopathic medicine from Touro University in California. He later completed his family practice residency in Miami, Florida.