Chronic Diarrhea
Loose stools have causes. Your gut is telling you something isn't right.
Diarrhea is a symptom, not a diagnosis.
Chronic diarrhea indicates dysfunction in gut absorption, motility, or microbiome balance. Bile acid malabsorption, SIBO, food intolerances, infections, and pancreatic insufficiency are common causes.
Finding and addressing the cause is essential—not just managing the symptom.
Common causes of chronic diarrhea
Bile Acid Malabsorption
When bile acids aren't properly reabsorbed, they reach the colon and cause watery diarrhea. This is more common than often recognized, especially after gallbladder removal.
SIBO
Small Intestinal Bacterial Overgrowth produces excess gas and irritates the gut lining, leading to loose stools, bloating, and nutrient malabsorption.
Food Intolerances
Lactose, fructose, gluten, and other food components can trigger inflammatory diarrhea. FODMAPs are common culprits in IBS-D.
Pancreatic Insufficiency
Without adequate pancreatic enzymes, fats aren't properly digested—leading to fatty, floating stools. This causes both diarrhea and nutrient deficiencies.
Nutrients for gut healing
These nutrients support gut healing and help resolve chronic diarrhea.
Supplement-Induced Diarrhea
Not all diarrhea comes from disease. Magnesium supplements (especially citrate and oxide forms) commonly cause loose stools. High-dose vitamin C can do the same.
Before investigating complex causes, check your supplements. Switching magnesium forms (to glycinate or malate) or reducing doses often resolves the issue.
"If diarrhea started after beginning supplements, that's likely your answer."
The histamine connection
Histamine intolerance commonly causes diarrhea:
- 1Histamine speeds up gut motility, causing loose stools
- 2DAO enzyme deficiency prevents histamine breakdown
- 3High-histamine foods trigger symptoms
- 4Diarrhea often comes with flushing, headaches, or hives
Resolving chronic diarrhea
Check supplements first
Magnesium citrate/oxide, high-dose vitamin C, and other supplements commonly cause loose stools. Rule this out before investigating further.
Test for infections
SIBO, parasites, and bacterial infections are common causes. Comprehensive stool testing can identify these issues.
Consider bile acid malabsorption
If diarrhea is watery and worse after fatty meals (especially post-gallbladder removal), bile acid sequestrants may help diagnostically and therapeutically.
Support gut healing
Once the cause is identified, zinc, glutamine, and vitamin A support gut lining repair. Appropriate probiotics help restore balance.