Diarrhea for Weeks—Why It Isn’t “Just Something You Ate”

Experiencing diarrhea for weeks can feel frustrating and uncomfortable. While occasional stomach upsets often resolve on their own, persistent diarrhea—defined as loose or watery stools lasting more than four weeks—warrants a closer look. Rather than assuming it’s “just something you ate,” understanding the possible causes and next steps can help you find relief and avoid complications.

Why Diarrhea Lasts Beyond a Meal

When diarrhea continues for weeks, simple dietary indiscretions are unlikely to be the sole cause. Your digestive tract is a complex system involving your intestines, liver, pancreas and even your hormones. Chronic diarrhea may stem from issues such as:

• Infections
  • Parasitic (e.g., Giardia) or bacterial overgrowth
  • Persistent viral infections in immunocompromised people

• Inflammatory Bowel Disease (IBD)
  • Crohn’s disease or ulcerative colitis causes chronic inflammation
  • Symptoms often include blood in stool, urgency and abdominal pain

• Irritable Bowel Syndrome (IBS)
  • A functional disorder leading to alternating diarrhea and constipation
  • No visible inflammation but significant discomfort and urgency

• Malabsorption Syndromes
  • Celiac disease (gluten intolerance)
  • Pancreatic enzyme insufficiency (cystic fibrosis, chronic pancreatitis)
  • Small intestinal bacterial overgrowth

• Secretory vs. Osmotic Causes
  • Secretory: your gut actively secretes water (e.g., certain tumors, bile salt malabsorption)
  • Osmotic: poorly absorbed substances draw water into the bowel (e.g., lactose, sorbitol)

• Medication and Toxin-Related
  • Antibiotics disrupting normal gut flora
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), certain heart or diabetes meds

• Endocrine Disorders
  • Hyperthyroidism speeds up bowel transit
  • Addison’s disease affects sodium and water balance

• Post-Surgical Changes
  • After gallbladder removal, bile salts can irritate colon
  • Bariatric surgery can alter nutrient absorption

• Liver and Pancreatic Disease
  • Cirrhosis can lead to fat malabsorption and diarrhea
  • Pancreatic cancer or chronic pancreatitis reduce digestive enzymes

When to Worry: Warning Signs

While not every case of diarrhea for weeks signals a life-threatening condition, certain “red flag” symptoms mean you should seek medical attention promptly:

• High Fever (over 102°F/39°C)
• Signs of Dehydration (dizziness, dark urine, dry mouth)
• Blood or Mucus in Stool
• Unintentional Weight Loss (more than 5% of body weight)
• Severe Abdominal Pain or Distention
• Symptoms in Immunocompromised Individuals

If you experience any of these, please speak to a doctor immediately.

How Doctors Approach Chronic Diarrhea

According to a systematic approach outlined by Korman et al. (1988) in American Family Physician, and updated in the Rome IV diagnostic criteria for bowel disorders (Mearin et al., 2016), clinicians typically follow these steps:

1. Detailed History & Physical Exam

   • Duration, stool characteristics, diet, travel, medication use
   • Family history of GI diseases

2. Basic Laboratory Tests

   • Complete blood count (CBC) for anemia or infection
   • Electrolytes and kidney function for dehydration
   • Celiac serology (tTG-IgA)

3. Stool Studies

   • Culture for bacteria, ova and parasites
   • Fecal leukocytes or calprotectin (for inflammation)
   • Fat quantification if malabsorption is suspected

4. Imaging & Endoscopy

   • Colonoscopy with biopsy (rule out IBD, microscopic colitis)
   • CT or MRI enterography (for small-bowel disease)

5. Specialized Tests

   • Hydrogen breath test (for lactose intolerance, bacterial overgrowth)
   • Secretin stimulation test (pancreatic function)
   • 72-hour fecal fat collection (steatorrhea)

6. Non-Invasive Liver Assessment

   • Transient elastography or serum fibrosis scores (per EASL-ALEH guidelines, 2015) when liver disease is suspected

Managing and Treating Chronic Diarrhea

Treatment depends on the underlying cause:

• Infections: Antibiotics or antiparasitic medications for confirmed pathogens
• IBD: Anti-inflammatory drugs, immunomodulators or biologics
• IBS: Dietary changes (low FODMAP), fiber supplements, stress management
• Malabsorption: Enzyme replacement, gluten-free diet, nutritional supplements
• Secretory Diarrhea: Bile acid binders (e.g., cholestyramine)
• Medication-Induced: Adjusting or substituting offending drugs
• Endocrine Causes: Treat underlying hormone imbalance

In all cases, general measures can help:

• Maintain hydration with oral rehydration solutions
• Eat small, frequent meals; avoid high-fat or high-sugar foods
• Consider probiotics to support healthy gut flora

Tracking Your Symptoms

Keeping a simple diary of food, stool patterns and associated symptoms (e.g., bloating, pain) can help you and your doctor spot triggers or trends.

You might also consider doing a free, online symptom check for to better understand which factors could be contributing to your diarrhea and to prepare for a conversation with your healthcare provider.

When to See Your Doctor

Persistent diarrhea for more than two weeks should prompt a medical evaluation. Early diagnosis often leads to better outcomes, whether the cause is Crohn’s disease, celiac disease, chronic pancreatitis or another condition. Remember:

• Don’t delay if red-flag symptoms appear
• Bring your symptom diary and any over-the-counter or prescription medication list
• Ask about relevant tests (blood, stool, imaging, endoscopy)

Conclusion

Diarrhea for weeks is not usually “just something you ate.” It often signals an underlying issue that may require targeted treatments—ranging from diet changes and enzyme supplements to immunosuppressive therapy or infection control. Understanding the spectrum of causes helps you take proactive steps toward relief.

If you’re concerned about ongoing diarrhea, start by tracking your symptoms and consider a free, online symptom check for . Above all, speak to a doctor about anything that could be life threatening or serious. Early medical attention is key to getting the right diagnosis and treatment plan.