- What Causes Diarrhea?
- Other possibilities
- Mild, Moderate, or Severe Diarrhea
- Topic Overview
- When Diarrhea Is More Serious Than You Think
- Traveler’s Diarrhea
- Diarrhea and Medications
- Diarrhea and Digestive Disorders
- Diarrhea After Surgery
- Diarrhea and Allergies
- Irritable Bowel Syndrome
What Causes Diarrhea?
Many different things can cause diarrhea.
Infections: You may get an infection from contact with someone else. You may get one after having contaminated food or water. If you eat something that was improperly cooked or contaminated after cooking, the infection is called food poisoning. Diarrhea, cramps, and vomiting are common with food poisoning. Children who attend day care and their families are more likely to get these infections.
People who travel to foreign countries get “traveler’s diarrhea,” usually after drinking bad water. Infectious diarrhea is a problem in developing countries, where it may be hard to keep waste water and sewage separate from water used to cook, drink, and bathe.
Medications: Many medicines can cause diarrhea. Some of the most common include:
- Antacids with magnesium
- Some antibiotics
- Chemotherapy drugs
- Cholesterol-lowering agents
- Thyroid hormone
Too much caffeine or alcohol: You may need to cut back on one or both to see if that does the trick.
Toxins such as insecticides, psychedelic mushrooms, and arsenic: They cause diarrhea, too.
A digestive problem: This could be lactose intolerance, celiac disease, or pancreatic problems.
Surgery to remove part of your small intestine: After that procedure, you may not be able to absorb everything you eat. Your doctor may call it short-bowel syndrome.
Removal of your gallbladder: The increase of bile in your colon from this procedure may result in watery stools.
Chronic diarrhea has many causes. Some are caused by disease. This article focuses mostly upon those causes where you can make changes that may result in a rapid improvement in the diarrhea.
This type of diarrhea is usually painless and persistent, and there are no signs of disease such as bleeding, anemia, weight loss, or fatigue. Frequent loose stools are a daily occurrence. There may be occasional normal stools. Despite the need to stay within reach of a toilet, the person is otherwise well.
Very frequently, the diarrhea is due to something in the diet that is taken in excess. Usually this is an excess of a sugar or chemical substance. Common examples are alcohol and caffeine. An excess of alcohol, especially beer and wine, may cause loose stools the next day. The best test is to stop alcohol completely and see if the diarrhea stops. If it does, drinking may be cautiously resumed at a more modest level.
Caffeine-containing drinks have a laxative potential. More than two or three cups of coffee or tea daily can often cause diarrhea. Withdraw gradually over the course of a few days to avoid headache and try going without for awhile. Decaffeinated drinks may still contain chemicals that can loosen the stools. Most people can tolerate smaller amounts well.
Some sugars can cause diarrhea. For example, the artificial sugar sorbitol is used as a sweetener. It is often used in diet gums and candies or as a sugar substitute in coffee or tea. It has no calories, but is a known laxative if taken in sufficient amount. Mannitol is another sweet substance frequently found with sorbitol.
Fructose is a natural calorie-containing sugar found in fruit. It is one reason why large amounts of fruit can cause diarrhea. It may also be found in candies, soft drinks, honey, and preservatives and, in sufficient amounts, can cause diarrhea. Many people notice that their bowel movements are looser and more frequent in the summer when fresh fruits and vegetables are freely available. Moderating intake should help.
Lactose intolerance is the cause of chronic diarrhea in some people. Lactose is a sugar that is contained in cow’s milk. Its proper digestion requires the adequate presence of an enzyme (lactase) in the wall of the small intestine. Treatment of lactose intolerance initially involves the elimination of all lactose-containing products from the diet. Moderate amounts of dairy or modified dairy products may be gradually reintroduced into the diet as tolerated.
Laxatives are frequently present in herbal medicines. Senna tea is an obvious example. But herbs with a laxative effect like senna can be found in many other popular remedies. The contents of an herbal remedy may not all appear on the package. Only by stopping the medicine for a trial period can one be confident that it is not the cause of chronic diarrhea.
Medications – Many regular medicines can have diarrhea as an unwanted side effect.
A list of suspects includes:
- antacids containing magnesium hydroxide
- stool softeners
- drugs for “regularity”
It pays to be cautious of any regularly consumed drug or “natural” remedy.
Allergies – True food allergies are rare as a cause of chronic diarrhea. If an elimination diet is embarked upon (they are very difficult), one must take care not to end up with a nutritionally deficient diet. Supervision by your doctor is important here.
Infections – Occasionally, chronic unexplained diarrhea may be due to an infection with an intestinal parasite. These are more common is some parts of the world. This may be detected in some cases by stool tests, or more accurately by a biopsy of the upper small intestine.
Surgeries – If one is suffering from chronic diarrhea, it is important to note if there have been previous intestinal operations. Diarrhea can sometimes be a complication. Inform your doctor of the precise nature of any previous abdominal surgery, since this type of diarrhea is often treatable.
If you have chronic diarrhea you should carefully review with your doctor all that you eat and drink, and your past surgical, drug, and travel history. This may disclose a cause that can be remedied.
Careful consideration of these everyday items may avoid extensive and costly tests and lead to earlier relief
Adapted from IFFGD publication #150 by W. Grant Thompson, MD, FRCPC, Emeritus Professor of Medicine, University of Ottawa, Ontario, Canada
- Functional Diarrhea
- Common Causes of Chronic Diarrhea
- Managing Diarrhea
- Nutrition Strategies for Managing Diarrhea
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Mild, Moderate, or Severe Diarrhea
Diarrhea is described as an increase in the frequency of bowel movements or a decrease in the consistency of stools that causes the discharge of watery, loose stools. The severity of diarrhea is determined by the size and number of stools passed within a period of time.
- Severe diarrhea means having more than 10 loose, watery stools in a single day (24 hours).
- Moderate diarrhea means having more than a few but not more than 10 diarrhea stools in a day.
- Mild diarrhea means having a few diarrhea stools in a day.
Severe diarrhea has many causes. Stomach flu (gastroenteritis) or food poisoning may cause severe diarrhea. Drinking untreated water that contains the Giardia lamblia parasite can cause diarrhea that develops 1 to 4 weeks later.
Severe diarrhea increases your risk of dehydration by causing your body to lose large amounts of fluid quickly. Be sure to increase your intake of fluids, such as water or a rehydration drink, and to watch for symptoms of dehydration.
Persistent diarrhea can have many causes, including dietary changes, stress, irritable bowel syndrome, and certain medicines. Occasionally, persistent diarrhea can be a symptom of a more serious condition, such as a chronic infection, inflammatory bowel disease, a malabsorption syndrome, or colorectal cancer.
When Diarrhea Is More Serious Than You Think
If you are traveling in a different part of the world and come down with diarrhea, there’s a pretty good chance that you have traveler’s diarrhea. As with most types of severe diarrhea, you should see your doctor if the symptoms stick around once you’re home. “If the diarrhea persists after the patient is back from a trip, the stool should be tested for parasites, and the patient should be evaluated for an underlying condition that has been unmasked by an infection — for example, inflammatory bowel disease,” said Dr. Charabaty. “After an episode of infectious diarrhea, the diarrhea can persist for several months to years because the gut flora and motility has been altered — that’s what we call post-infectious diarrhea or post-infectious IBS.”
Diarrhea and Medications
Medications to treat certain conditions are very common causes of diarrhea. Hundreds, in fact, may be to blame, said Dr. Kussin. Luckily, when it comes to medicine and diarrhea the advice is fairly straightforward. “If a new medication is started and diarrhea follows within a few days to weeks, your doctor may want to stop the agent and see what happens,” said Kussin. “There are so many therapies for so many conditions that if a medication causes diarrhea, there are alternatives that can take its place.”
Diarrhea and Digestive Disorders
Medical conditions such as ulcerative colitis, Crohn’s disease, and celiac disease can also cause of diarrhea. Ulcerative colitis can lead to sores or ulcers on the internal lining of the colon, resulting in frequent bouts of diarrhea and abdominal cramps. “Crohn’s is a chronic inflammation of the gastrointestinal tract that often manifests with diarrhea as well as abdominal pain, blood in the stool, anemia, and sometimes weight loss and fever,” said Charabaty. “Celiac disease is a disease caused by an allergy to gluten, which is a protein present in wheat, rye, and barley. In patients with celiac disease, gluten is toxic to their small bowel, destroying its normal lining. This in turn prevents the absorption of water and nutrients, causing not only diarrhea, but also weight loss, anemia, osteoporosis, and other intestinal and extraintestinal symptoms.”
Diarrhea After Surgery
A variety of surgeries in and around the digestive tract can cause short-term diarrhea as a potential side effect. In most cases, this should pass after a few days, but see your doctor if it continues unabated. “Resection of part of the small bowel or the large bowel can cause diarrhea because we are removing a portion of the gut responsible for absorbing water,” said Charabaty. “Certain types of surgeries also promote small bowel bacterial overgrowth, which in turn can cause diarrhea. Removal of the gallbladder can also cause diarrhea because of the bile salts irritating the colon and causing leakage of water into the colon lumen.”
Diarrhea and Allergies
It’s not a common symptom, but some people who experience the red eyes, runny nose, sneezing, and wheezing of allergies in the spring may also have a case of diarrhea on top of it all. “Diarrhea as the sole symptom of seasonal allergies would be uncommon,” said Kussin. “As a part of a suite of symptoms that recurs yearly, then it is likely caused by a sensitivity to an environmental allergen.” In addition to other diarrhea medications, Kussin said that this symptom may respond to antihistamines just like your other allergy symptoms.
With any underlying disorder causing your diarrhea, your doctor will likely treat the diarrhea along with the other symptoms of the condition to get you feeling better.
Irritable Bowel Syndrome
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What Is Irritable Bowel Syndrome?
Irritable bowel syndrome (IBS) is a common intestinal disorder that affects the colon (the large intestine). The colon’s main job is to absorb water and nutrients from partially digested food. Anything that is not absorbed is slowly moved through the colon toward the rectum and out of the body as waste in the form of feces (poop).
Muscles in the colon work to get rid of the body’s waste products. They contract and relax as they push the undigested food through the large intestine. These muscles also work with other muscles to push the waste out of the anus.
If the muscles in the colon don’t work at the right speed for proper digestion or if the coordination with muscles in the rectum or pelvis is interrupted, the contents of the colon can’t move along smoothly. When this happens, a person can feel the belly cramps, bloating, constipation, and diarrhea that may be signs of IBS.
Who Gets Irritable Bowel Syndrome?
A lot of teens have IBS. It’s estimated that between 6% and 14% of all teens have IBS symptoms. It seems to affect more girls than guys.
The good news is that although IBS can be uncomfortable, embarrassing, and even painful, it’s not life threatening. And, unlike other digestive conditions, such as inflammatory bowel disease, IBS doesn’t carry a risk of permanent damage to the intestines.
What Are the Signs & Symptoms of IBS?
The symptoms of IBS are usually recurring. This means that a person will have bouts of symptoms on an ongoing basis rather than just once or twice a year. People with IBS often notice their symptoms flare up at certain times. For some people, it’s whenever they eat a large meal. For others, it’s when they’re under a lot of pressure or stress. Some girls notice that they get IBS symptoms around the time of their periods.
The main symptom of IBS is belly pain or discomfort (bloating, etc.). Of course, having a stomachache, gas, or bloating once in a while doesn’t mean a person has IBS.
People with IBS have at least two of these symptoms:
- pain or discomfort that is relieved when they go to the bathroom and have a bowel movement
- pain or discomfort along with changes in their regular bowel movement patterns (for example, going to the bathroom a lot more or a lot less than usual)
- pain or discomfort along with changes in the way the stool (poop) looks. Some people become constipated and their stools get hard and difficult to pass; other people get diarrhea.
Because IBS is a problem with the colon, and the colon removes water from unprocessed food waste, it’s common for people with IBS to be constipated or have diarrhea:
- Constipation happens when waste matter remains in the colon for too long so that too much water is absorbed. This makes the stool hard and difficult to pass.
- If the muscles in the colon move the contents along too fast, though, the colon doesn’t have a chance to remove enough fluid, so the person gets diarrhea.
What Causes Irritable Bowel Syndrome?
No one knows exactly what causes IBS, although it tends to run in families.
A prior infectious illness (such as gastroenteritis) may increase a person’s risk for IBS. Exposure to a bacterial or viral infection can cause
that can change how the gastrointestinal system works.
Stress can also play a part in IBS. Stress can accelerate your colon and slow your stomach.
Foods can also be a trigger, but this is hard to predict. For example, a high-fat diet may bother some people, but not others. Eating big meals and spicy foods often cause problems, as do drinks with caffeine (coffee or soda), alcohol, milk and milk products, and grains like wheat, barley, or rye. Some of these foods are linked to other digestive conditions like lactose intolerance or celiac disease, though, so it’s important to see a doctor if you think a food is causing digestive problems.
Some medicines, like
, can trigger IBS symptoms in people who have the disorder.
How Is Irritable Bowel Syndrome Diagnosed?
There is no specific test to diagnose IBS. Doctors usually diagnose it based on a physical exam and a patient’s symptoms. For example, if someone has had belly pain for more than 12 weeks out of the previous year (not necessarily 12 weeks in a row), it’s a sign to a doctor that IBS may be a possibility.
A doctor will probably ask how often you have stomach or gas pain, whether you’re ever constipated or have diarrhea, and if so, how long these problems last. He or she may ask questions about your bathroom habits, such as whether your bowel movements are regular, what your stools look like, and whether you ever feel like you need to have a bowel movement but then can’t.
It may feel embarrassing or even silly to answer these questions, but learning as much as possible about your symptoms will help the doctor diagnose what’s going on.
Besides doing an exam, the doctor will ask you about any concerns and symptoms you have, your past health, your family’s health, any medicines you’re taking, any allergies you may have, and other issues. This is called the . You may need to ask a parent or other adult for some information.
Although there’s no test for IBS, a doctor may send a patient for tests to make sure the symptoms aren’t being caused by other problems.
How Is Irritable Bowel Syndrome Treated?
There’s no cure for IBS. But there are ways to take control of IBS symptoms. Here are some of the things that doctors recommend:
- Diet changes. Some people with IBS find that careful eating helps ease or stop IBS symptoms. You might try avoiding very large meals, drinks with caffeine, spicy or fatty foods, chocolate, some dairy products, and foods that contain gluten. Some people find that adding fiber — eating more fruits and vegetables, for instance — and drinking more water can help stop IBS symptoms, too.
Also try eating regular meals, avoiding on-the-run eating, and paying attention to good nutrition.
- Lifestyle changes. If you have IBS that appears related to stress, you might want to make some changes. Consider ways to manage daily pressures, such as schoolwork, and make time for activities you enjoy.
Be sure to get enough sleep and exercise. Your doctor might recommend some stress-reduction techniques, like breathing exercises. Research also shows that hypnotherapy may help in managing IBS.
- Medicines. For some people with severe IBS, doctors may suggest one of several prescription or over-the-counter medicines. Depending on the symptoms, doctors may recommend over-the-counter laxatives (for constipation) or anti-diarrhea medicines, or might prescribe muscle relaxers (for colon muscle spasm) or antidepressants (for anxiety and stress). Before trying any over-the-counter medicines, talk to your doctor first to be sure you get the best one for you.
Your doctor will have suggestions on what might work for you. You also can keep a food diary so you can see if some foods and events seem to trigger your IBS symptoms. Record what you eat, what symptoms you have, and when they happen.
What’s Life Like for Teens With Irritable Bowel Syndrome?
If you’re living with IBS, you may worry about anything that could trigger symptoms — even otherwise fun events like playing in a championship game or going out for a fancy dinner before the prom.
Learning more about IBS and what triggers your symptoms is the first step to taking action. Then, do what you need to take care of yourself, whether that’s reducing stress by talking over problems with a school counselor or therapist, or watching out for spicy food.
Reviewed by: J. Fernando del Rosario, MD Date reviewed: October 2016