Causes of Loose Stool and How to Fix Them

We all get loose stools or diarrhea from time to time. While stool can be watery, liquid, and show classic signs of food poisoning or the stomach flu, other times bowel movements are simply softer than normal without a clear cause. Here's a look at 14 causes of loose stool (whether it’s a stool that is solid but mildly loose, mushy, shapeless, or full-blown diarrhea).

causes of loos stool include food or medications and various health conditions
Illustration by Joshua Seong, Verywell

Food or Drink

Several types of food and drink can result in loose stools.


A type of sugar in fruit, fruit juice, honey, and some vegetables, fructose is also found in table sugar and high-fructose corn syrup (used to sweetened processed foods and beverages). If large amounts are consumed or if you have a condition such as fructose malabsorption, fructose can cause loose stools or diarrhea, gas, or abdominal pain.

If you consume high-fructose foods such as juice, honey, agave syrup, high-fructose corn syrup, molasses, or palm or coconut sugar, limiting your serving sizes may help.

Sugar Alcohols

Some people find that sugar alcohols, which include xylitol, mannitol, sorbitol, erythritol, and other artificial sweeteners, have a laxative effect. Often used as artificial sweeteners (in sugarless candy and gum, diet beverages, and sugar substitutes), sugar alcohols are also found naturally in food. Sorbitol, for instance, is found in peaches, apples, pears, and prunes.

Sugar alcohols are not well absorbed. As a result, consuming excessive amounts causes the sugar alcohols to pull water from the bloodstream into the intestines, resulting in diarrhea and loose stools.

Consume sugar alcohols in moderation. If you rely on artificial sweeteners to manage diabetes or other health conditions, talk with your healthcare provider about using a variety of sweeteners and consuming them in moderation.


Drinking coffee can stimulate the contraction and relaxation of intestinal muscles (called peristalsis), promoting bowel movements. Coffee's acidity also causes the body to produce more bile, which can cause looser stools.

Aside from the bowel-stimulating quality, coffee can also result in looser stools because as stool moves through the colon quickly, there is less time for water to be reabsorbed by the body (and stool to firm up).

Try darker roasts, like French roast, which tend to have less caffeine than lighter roasts. Also skip the milk or cream, excess sugar, and sweeteners such as sorbitol, which can also trigger loose stools.

Oily Foods

A greasy meal or a higher fat diet (such as the keto diet) can trigger bowel movements and loose stools in some people. Food in the stomach and small intestine (particularly fatty food) triggers contractions in the colon and the movement of stool. Called the gastrocolic reflex, these contractions in the large intestine may lead to a bowel movement a short time after eating.

Certain conditions like chronic pancreatitis can also result in oily loose stools or diarrhea. Although a fatty meal can trigger loose stools, speak with your healthcare provider if it's a regular occurrence.

Spicy Food

Hot and spicy foods can irritate the intestinal lining and cause loose stools. It normally happens after a spicy meal and returns to normal shortly afterward. Compounds in spicy food aren't absorbed by the body and make their way into your intestines.

Although not everyone who eats spicy food has loose stools, if it happens to you, try limiting your intake of spicy food. Eating yogurt, rice, or bread may help offset some of the effects of spicy food on the intestines.


Ethanol in alcohol speeds up the contractions in the colon, which means that waste is moved through the intestines faster and there's less time for the colon to absorb water, which can lead to watery stool.

If you notice that drinking affects your stools, try seeing whether wine and spirits give you less digestive trouble than beer or malt liquor. Cutting back on your overall intake will also help.


The use of certain herbal remedies or medications may lead to the passage of loose stools. Some of the medications and supplements include:

  • Antacids containing magnesium hydroxide
  • Antibiotics
  • Chemotherapy
  • Magnesium 
  • Senna

Research suggests that probiotics may help prevent diarrhea that can occur after taking antibiotics. The American Gastroenterology Association released a 2020 consensus on the use of probiotics after a systematic review of previously published studies. Regardless of age, the majority of gastroenterologists agreed there is benefit in taking a probiotic for the prevention of C. difficile infection. A report published in Nutrition in Clinical Practice in 2016, which involved the analysis of previously published clinical trials testing the effects of probiotics on people with antibiotic-associated diarrhea.

Their analysis revealed that probiotics were associated with a reduced risk of antibiotic-associated diarrhea in adults (but not in those over the age of 65). According to another study, Lactobacillus rhamnosus GG is the most effective strain for antibiotic-associated diarrhea.

Chronic Medical Conditions

Loose stools may also be seen in a variety of health conditions.

Lactose Intolerance

A naturally occurring sugar, lactose is found in milk, ice cream, cheese, and other dairy products. Many adults have a low level of lactase, an enzyme that breaks lactose down. Consuming milk or dairy can lead to loose stools and diarrhea in people with lactose intolerance.

Irritable Bowel Syndrome

A condition that affects the large intestine, irritable bowel syndrome (IBS) can cause cramping, abdominal pain, gas, bloating, constipation, and diarrhea. Symptoms vary widely from person to person. Some people have loose stools or diarrhea, while others have constipation or alternate between the two.

Celiac Disease

Gluten products like bread, pasta, and baked goods are a problem for people with celiac disease. A protein found in wheat, barley, and rye, gluten causes an autoimmune reaction in people with celiac disease. One of the symptoms can be diarrhea or loose stools.

The condition can cause low energy, unintended weight loss, and a lack of growth. If the condition is untreated, it may be hard to link gluten-containing foods to symptoms because of damage to the intestinal lining.

Dumping Syndrome

A condition is seen most often seen in people who have had bariatric (weight loss), esophageal, or gastric surgery, dumping syndrome is when the food you eat moves too quickly from your stomach into your small intestine, causing loose stools.

Other Chronic Health Conditions

Loose stools may be seen in these conditions:

These conditions can be diagnosed or managed, so it's best to work with your healthcare provider if you suspect having them or have been diagnosed.

Stomach Flu

The stomach flu can cause diarrhea, vomiting, cramps, fever, and headache. Also known as viral gastroenteritis, it's highly contagious.

Viruses (such as noroviruses, rotaviruses, and adenoviruses) target the digestive tract and result in inflammation of the stomach and intestines, diarrhea, vomiting, and cramps.

Symptoms typically appear one to three days after you've been infected and can range from mild to severe. Eating foods such as bananas, rice, applesauce, and toast may help. Young people, older adults, and people with weak immune systems are at risk for dehydration and should be watched carefully.

Food Poisoning

Also known as bacterial gastroenteritis, food poisoning is the result of eating food that has been undercooked, stored too long at room temperature, or not reheated properly and is contaminated with bacteria such as salmonella or E.coli. The result is inflammation in your stomach and intestines, and symptoms that can include diarrhea, vomiting, abdominal cramps, and nausea.

For mild cases, staying hydrated and eating potassium-rich foods may help ease symptoms, although some people require treatment.

When to See Your Healthcare Provider

Many cases of loose stool are the result of something you ate and will quickly return to normal. When it happens, it normally lasts two to three days. Some people get loose stool more often, due to dietary changes or as part of irritable bowel syndrome (IBS) or other conditions. You should consult your healthcare provider if your symptoms don't resolve or become a regular occurrence.

Emergency Symptoms

See a medical professional immediately if you have any of the following symptoms:

  • Severe abdominal pain
  • Blood or pus in the stool
  • Black or tar-colored stool
  • Chills, vomiting, lightheadedness, dizziness, or fainting
  • Confusion
  • Dehydration (dry mouth, infrequent or dark urination)
  • Fever 102 F or higher or lasting longer than several days
  • Rapid heart rate
  • Unexplained weight loss

Also, call your healthcare provider if you are an older adult, recently hospitalized, pregnant, or have a compromised immune system (e.g. take steroids, transplant rejection medications, or TNF-alpha inhibitors such as infliximab or etanercept).

Understandably, it's an uncomfortable topic to talk about, but your healthcare provider understands and is there to help. The conversation may make you uncomfortable but will provide relief for your symptoms.

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10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Dinicolantonio JJ, Lucan SC. Is fructose malabsorption a cause of irritable bowel syndrome? Med Hypotheses. 2015;85(3):295-7. doi:10.1016/j.mehy.2015.05.019

  2. Mäkinen KK. Gastrointestinal disturbances associated with the consumption of sugar alcohols with special consideration of xylitol: scientific review and instructions for dentists and other health-care professionals. Int J Dent. 2016;2016:5967907. doi:10.1155/2016/5967907

  3. International Foundation for Gastrointestinal Disorders. Common causes of chronic diarrhea. Updated October 2, 2019.

  4. Harvard Health Publishing. Is something in your diet causing diarrhea? Updated December 15, 2019.

  5. Su G, Ko C, Bercik, P, ET al. AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders. Gastroenterology. June 9 2020. doi:

  6. Jafarnejad S, Shab-Bidar S, Speakman JR, Parastui K, Daneshi-Maskooni M, Djafarian K. Probiotics reduce the risk of antibiotic-associated diarrhea in adults (18-64 years) but not the elderly (>65 years): a meta-analysisNutr Clin Pract. 2016 Aug;31(4):502-13. doi:10.1177/0884533616639399.

  7. Agamennone, V., Krul, C.A.M., Rijkers, G. et al. A practical guide for probiotics applied to the case of antibiotic-associated diarrhea in The NetherlandsBMC Gastroenterol 18,103 (2018). doi:10.1186/s12876-018-0831-x

  8. Centers for Disease Control. The symptoms of norovirus. Reviewed November 25, 2019.

  9. Cleveland Clinic. Gastroenteritis. Reviewed March 20, 2016.

  10. U.S. Department of Health and Human Services, National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of diarrhea. November, 2016.

Additional Reading
  • Su G, Ko C, Bercik, P, ET al. AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders. Gastroenterology. June 9 2020;doi: