Ilyas Memon, MD

Loose Stools: Common Causes and Helpful Treatments

Oct 05, 2023

Loose Stools: Common Causes and Helpful Treatments

Having loose, watery stools for a day or two is annoying, but it can be concerning when runny bowel movements persist for weeks. Learn about the common causes of acute and chronic diarrhea, and determine which treatments can help.

Virtually everyone has diarrhea at some point or another: Loose, watery stools are part of a standard immune system response to common infections as well as food poisoning; they’re also a frequent side effect of antibiotics and various gastrointestinal (GI) troubles.  

 Most of the time, diarrhea is a short-term (acute) problem that lasts a few days and subsides without medical care. Sometimes, however, liquid bowel movements persist longer — or become an ongoing (chronic) occurrence — signaling the possibility of a more serious issue.  

If you’re dealing with persistent, unexplained diarrhea, board-certified gastroenterologist Ilyas Memon, MD, and our expert team at Texas Digestive Disease Consultants can help. Read on as Dr. Memon explores common causes and effective treatments for loose stools. 

From normal stool to diarrhea 

Normal bowel movements are about 75% water and 25% protein, fat, mucus, and dietary fiber. As solid waste products move through your upper GI tract, they collect digestive fluids and electrolytes. Because your lower GI tract absorbs excess digestive fluids before waste reaches your colon, your exiting stool is firm and solid.   

With diarrhea, the digestive process is accelerated or intensified. It may occur when:

  • The upper GI tract produces excessive amounts of fluids and electrolytes
  • The lower GI tract doesn’t absorb excess fluid from moving waste quickly enough
  • The upper GU tract secretes excess fluids, and the lower GI tract doesn’t absorb it properly

Diarrhea is any bowel movement that’s more liquid than normal, occurs more often than normal, or expels a much higher stool volume than usual. Specifically, “having diarrhea” means passing loose, watery stools three or more times in one day. 

Common causes of loose stools

Diarrhea can be caused by various underlying problems, each of which is classified as acute or chronic based on its duration. Let’s take a closer look:

Causes of acute diarrhea 

Acute diarrhea typically lasts one or two days. Common causes include: 

Bacterial infections

Contracted through contaminated foods, Salmonella and E. coli are two of the most frequent bacterial infections associated with severe loose stools that resolve within a few days. 

Viral infections

Rotavirus, norovirus, and viral gastroenteritis (the stomach flu) are common viral infections that cause acute diarrhea. 

Parasitic infections

Contact with parasites such as Giardia lamblia or Cryptosporidium, which are found in contaminated drinking water, food, and recreational water, can also cause runny bowel movements for a few days.   

When acute diarrhea lasts for two or three weeks before it resolves, it’s called persistent diarrhea. Persistent diarrhea is usually a sign of a lingering infection. 

Causes of chronic diarrhea 

Chronic diarrhea persists for four weeks or longer. Whether it’s continuous or comes and goes over time, chronic diarrhea is more likely to be caused by:

Prescription medications

Several medications can cause chronic diarrhea with long-term use, including certain acid reflux medications and antidepressants, many antibiotics, and chemotherapy drugs.  

Food allergies and intolerances

Ongoing loose stools are often a problem for people with undiagnosed food intolerances, such as lactose (milk sugar) or fructose (fruit sugar) intolerance. Mild, undiagnosed allergies to soy, eggs, cereal grains, and seafood can also trigger chronic diarrhea.  

Bowel disorders and diseases

Long-standing diarrhea can also be a warning sign of a functional bowel disorder like irritable bowel syndrome (IBS) or a symptom of serious inflammatory bowel disease (IBD) like ulcerative colitis or Crohn’s disease.

Helpful treatments for diarrhea 

While acute diarrhea typically resolves on its own without medical intervention, it’s important to drink plenty of fluids for the duration of the episode to prevent dehydration. Otherwise, you can take over-the-counter anti-diarrhea medication for quick relief. It’s also helpful to:

  • Avoid alcohol, caffeine, and dairy
  • Choose low-fiber foods that help firm your stool
  • Avoid foods and beverages that give you gas

 The BRAT diet (bananas, rice, applesauce, and toast) can be especially helpful during a bout of acute diarrhea. If loose stools last longer than a few days — especially if they’re bloody or accompanied by fever — give us a call right away.  

 Diarrhea that persists or becomes chronic always requires a medical evaluation. Even if you avoid dehydration, long-lasting diarrhea can lead to malabsorption, a condition in which your small intestine no longer absorbs nutrients from your food. 

Treatment for persistent or chronic diarrhea depends entirely on its underlying cause. After a comprehensive evaluation, Dr. Memon may recommend:

  • Medication to treat a diagnosed infection
  • Probiotics to restore healthy gut microbiota  
  • Medications to treat an underlying GI condition
  • Dietary and lifestyle changes to minimize IBS
  • Comprehensive care to manage bowel disease

If you have persistent or chronic diarrhea, don’t delay: Call or click online to schedule a visit at Texas Digestive Disease Consultants in The Woodlands, Magnolia, and Willis, Texas, today.