What Are the Causes and Fixes of Loose Stool?

Loose stool can be distressing if it happens suddenly and you don't know what caused it. The first thing you might assume is that it was something you ate. While certain foods can definitely cause diarrhea, abdominal cramping, bloating, and gas, these symptoms could also be due to medications you are taking or an undiagnosed medical condition.

This article takes a look at some of the more common causes of loose stools as well as simple fixes to help avoid future bouts.

Food and Drink That Can Cause Loose Stool

Certain food and drinks can cause loose stools. Some can also ferment in the intestines and produce excessive gas, leading to stomach cramps, bloating, and flatulence ("wind").

Fructose

Fructose is a naturally occurring sugar. If you consume large amounts of fructose or your body doesn't process fructose well, it can cause loose stools, diarrhea, gas, or abdominal pain. This is called fructose intolerance.

If you have fructose intolerance, you will want to limit certain foods like:

• Fruit, especially apples, grapes, and watermelon
• Certain vegetables, such as asparagus, peas, and zucchini
• Fruit juice
• Honey
• Agave syrup
• Molasses
• Table sugar
• Palm or coconut sugar
• High-fructose corn syrup

Sugar Alcohols

Sugar alcohols, also known as polyols, occur naturally in fruits but are also used as sweeteners and bulking agents. While they have half to one-third fewer calories than table sugar, sugar alcohols are not well-absorbed and have a laxative effect if consumed in excess.

These include:

• Xylitol
• Mannitol
• Sorbitol
• Erythritol
• Allulose

Sugar alcohols are often used in sugar-free candy and diet drinks, Some are also found naturally in food like berries, peaches, apples, apricots, pears, plums, cherries, and prunes.

To fix the problem, limit your intake of artificial sweeteners and avoid overeating fruits or fruit juices that are high in polyols.

Coffee

Caffeine can increase the normal wave-like contractions of the intestines, called peristalsis. If you drink too much caffeine-containing liquid, these contractions can increase, giving the body less time to absorb water as stools pass through the digestive tract. The result is a looser, more watery stool.

Some coffee drinkers are more vulnerable to this and may develop diarrhea after just a couple of cups. Caffeine in tea, coffee, cocoa, chocolate, and energy drinks can have the same effect.

If you have diarrhea after drinking coffee, try darker roasts (like French roasts) that have less caffeine than lighter roasts. You should also skip the milk, cream, excess sugar, and artificial sweeteners that also cause loose stools.

Greasy Foods

Diarrhea is a common feature of a high-fat diet, but even a single large helping of fried or greasy food can trigger loose stools in some people.

Fried or fatty foods are not well-absorbed. As they move through the intestines, they are broken down into fatty acids, which cause the intestines to secrete excess fluids, leading to diarrhea. The fatty acids also irritate the intestines, causing stools to move faster through the system than normal.

To prevent this, avoid fatty or greasy food like fries, burgers, fried chicken, potato chips, pizzas, onion rings, doughnuts, and even fatty cuts of red meat.

Spicy Foods

Hot and spicy foods can irritate the intestinal lining and cause loose stools. That's because some compounds in spicy food aren't absorbed and can irritate the lining of the intestines, triggering the gastrocolic reflex. This is the body's response to food that signals when and how fast the intestines need to move.

Not everyone who eats spicy food has loose stools. If it happens to you, limit your intake of spicy food. Eating yogurt, rice, or bread may help offset some of the intestinal irritation.

Alcohol

Ethanol in alcohol speeds up peristalsis, moving stools through your body faster. With less time to absorb water, stools will become looser and more watery. Certain alcoholic beverages are also more irritating to the intestines, including fermented beverages like beers.

If you notice that drinking causes loose stools, try drinking beverages that are lower in alcohol (like wine or hard cider). Cutting back on your overall intake will almost certainly help.

Food Poisoning

Also known as bacterial gastroenteritis, food poisoning is caused by eating food that has been contaminated with bacteria like salmonella or E.coli. This can happen when food hasn't been cooked properly or has been kept for too long at room temperature.

To avoid food poisoning:

• Wash your hands and work surfaces before, during, and after preparing food.
• Separate raw meat, poultry, seafood, and eggs from ready-to-eat foods.
• Cook food to a safe internal temperature, using a food thermometer.
• Keep your refrigerator set at 40 F or below.
• Refrigerate leftovers within two hours of cooking or within one hour if the food has been exposed to temperatures over 90 F (such as after a picnic).

What Medications Cause Loose Stool?

Certain prescription drugs, over-the-counter medications, nutritional supplements, and herbal remedies can cause loose stools. Some do this by affecting peristalsis, while others affect the absorption of food or directly irritate the intestines.

Others affect the normal bacterial flora of the intestines. With antibiotics especially, the elimination of helpful bacteria can lead to the rise of harmful ones like Clostridioides difficile. C. difficile (or C. diff) is a common cause of watery and sometimes explosive diarrhea along with gas, bloating, and cramping.

Medications or supplements that can cause diarrhea include:

• Antacids
• Antibiotics
• Chemotherapy
• High-dose vitamin C supplement
• Immunosuppressants like mycophenolate
• Licorice root
• Metformin
• Magnesium supplements
• Multivitamin supplements
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Proton pump inhibitors
• Senna

If a medication or supplement you're taking is causing loose stools, talk to your healthcare provider. A different drug or formulation might be better for you.

Some research suggests probiotics can help prevent or manage antibiotic-associated diarrhea (AAD). A 2016 review of studies published in Nutrition in Clinical Practice found that probiotics containing Lactobacillus rhamnosus were especially useful in reducing the risk of AAD.

Medical Conditions That Can Cause Loose Stool

Loose stools may not be caused by something you ate but rather by something you have. These include medical conditions that affect the normal breakdown of foods, trigger an abnormal immune response, or increase peristalsis.

Lactose Intolerance

Lactose is a natural sugar found in dairy products like milk and cheese. Many adults have a low level of lactase, an enzyme that breaks down lactose. If your body doesn't digest lactose well, eating or drinking dairy products may give you diarrhea. This is called lactose intolerance.

You can avoid the symptoms of lactose intolerance by limiting your intake of dairy products. You can also choose lactose-reduced milk products, including ice cream, or add a liquid or powder lactase enzyme to milk to break down lactose.

There are also lactase tablets you can take before eating or drinking milk products.

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a poorly understood disorder that causes abdominal pain, gas, bloating diarrhea, and constipation. Symptoms vary from person to person. Some have loose stools or diarrhea, while others have constipation or both.

IBS is diagnosed when no other causes of your symptoms can be found.

Different foods can trigger IBS symptoms in different people. Because of this, you may need to work with a healthcare provider or nutritionist to pinpoint your individual triggers. IBS attacks can often be prevented with a high-fiber diet and the avoidance of fermentable foods called FODMAPs.

Celiac Disease

Celiac disease (CD) is an autoimmune disorder in which the immune system responds abnormally to food containing gluten, attacking the cells of the intestine as if they were intruders. Symptoms include diarrhea, gas, bloating, and cramping.

If left untreated, CD can severely damage the intestines and lead to extreme weight loss.

CD is treated by avoiding gluten found in products made with wheat, barley, rye, or triticale (a cross between wheat and rye). This includes processed foods like bread, pasta, cereal, and pizza. You can also find gluten in whiskey since components of rye are involved in fermentation.

Dumping Syndrome

People who have had abdominal surgery can sometimes develop dumping syndrome. This is when food moves out of the stomach too quickly, causing diarrhea, cramping, nausea, lightheadedness, and a rapid heartbeat.

Dumping syndrome can occur with surgeries involving the intestines, gallbladder, appendix, pancreas, stomach, and liver as well as bariatric (weight-loss) surgery.

Dumping syndrome is treated with changes in eating habits, such as:

• Eating smaller portions
• Eating several smaller meals rather than three big ones
• Eating slowly and chewing your food more thoroughly
• Eating softer or pureed foods
• Choosing lean protein, healthy fats, and foods high in fiber
• Avoiding processed foods and foods that are high in sugar
• Drinking water 30 to 60 minutes before and after eating

Other Chronic Health Conditions

Loose stools go hand in hand with these conditions:

• Bile acid diarrhea
• Crohn's disease
• Hyperthyroidism
• Ulcerative colitis
• Parasitic infections
• Bacterial infections 
• Small intestinal bacterial overgrowth (SIBO)

If you have diarrhea that doesn't go away, see a healthcare provider. Many of these conditions can be treated or managed.

When to See a Healthcare Provider

Sometimes, a loose stool is caused by something you ate. In these cases, your stool will usually return to normal within two to three days. If diarrhea persists, it may be due to something more serious.

Irrespective of the cause, it's important to seek treatment for persistent or severe diarrhea. If left untreated, severe diarrhea can lead to extreme dehydration, a steep drop in blood pressure, and shock.

Summary

A loose stool is one that's softer or more like liquid than normal. Having three or more loose stools in a day means you have diarrhea.

Loose stools and diarrhea can be a temporary problem. That's especially true if they were caused by something you ate or a medication you took. They can also be caused by illness, infection, or a long-term health condition.

If your symptoms don't get better in a few days, check with a healthcare provider to find the exact cause. Some of the conditions that cause loose stools can be serious, but many can be treated successfully.