There are many reasons why you might develop diarrhea after drinking water, such as sulfate contamination, IBS, overhydration, or malabsorption of a substance like lactose.
Diarrhea is defined as passing loose and watery stool more than
- infections
- food intolerances
- gastrointestinal (GI) conditions like irritable bowel syndrome (IBS)
Drinking water is an uncommon trigger. There are several reasons why water might cause diarrhea, including:
- the water contains a substance that stimulates your bowels
- stretching of your stomach is triggering your gastrocolic reflex
- you’re drinking too much water
- your intestines can’t absorb the water
Read on to learn about some of the reasons water may trigger diarrhea.
Here are some potential reasons why you may get diarrhea after drinking water.
High sulfate levels
High sulfate levels in your drinking water can cause diarrhea and dehydration, especially if your body isn’t used to it. Children and adults usually build a tolerance to sulfate levels after a few days.
The U.S. Environmental Protection Agency (EPA) has set the maximum allowable sulfate level at 250 milligrams per liter. Amounts higher than this tend to have a bitter taste.
Osmotic diarrhea
Osmotic diarrhea occurs when components of your food stay in your bowel without getting absorbed and draw water into your intestines. Excess water in your bowel can lead to watery stools.
Potential causes include:
malabsorption of lactose in milk products- certain laxatives like lactulose and citrate of magnesia
- malabsorption of bile salts in people with Celiac disease
- infections like rotavirus that
damage cells the cells lining your intestines - exposure to cytotoxins produced by bacteria like Escherichia coli (E. Coli) or Shigella dysenteriae serotype 1
Water intoxication (water poisoning)
Water intoxication happens when you drink large amounts of water in a short period of time, which can dilute electrolytes in your blood and cause life threatening symptoms, such as:
- nausea and vomiting
- altered mental state
- confusion
- high blood pressure
- increased pressure around your brain (intracranial hypertension)
- diarrhea
Water intoxication is
- drinking excessive water after exercise without replenishing electrolytes
- a condition called psychogenic polydipsia, which is compulsive water-drinking
- over-replenishing water if you have a condition causing high antidiuretic hormone levels
Irritable bowel syndrome
Your gastrocolic reflex helps control the mobility of food through your GI tract. When your stomach stretches, this reflex increases muscular contractions to help pass food through.
A problem with the gastrocolic reflex is a
In theory, drinking a lot of water could stretch your stomach and provoke the gastrocolic reflex.
Dumping syndrome
Dumping syndrome is when food passes through your stomach too quickly, usually within 30 minutes of a meal. It can cause symptoms like:
- diarrhea
- bloating
- nausea
- abdominal pain
- stomach growling
Traveler’s diarrhea
Traveler’s diarrhea occurs when you’re traveling to areas where the food or water is contaminated with:
- bacteria
- viruses
- parasites
E. coli is the most common cause of traveler’s diarrhea, making up about
Dysentery
Dysentery is a GI infection caused by bacteria or amoebae that can cause osmotic diarrhea. Potential bacterial causes include:
- Shigella
- E. coli
- Campylobacter
- Salmonella
Amebic dysentery is rare in the United States and usually develops in people who have recently visited tropical regions.
Medication use
Some medications can cause osmotic diarrhea, such as:
- magnesium-containing laxatives
- antacids
- the laxative lactulose
Food poisoning
Food poisoning develops when you consume food containing harmful bacteria. Some types of bacteria that cause food poisoning, such as E. coli, can cause osmotic diarrhea.
Other causes
Other potential causes of diarrhea after drinking water include:
- conditions that cause carbohydrate malabsorption, such as:
- lactose intolerance
- sucrose-isomaltose deficiency
- glucose-galactose malabsorption
- Crohn’s disease
- taking too many laxatives
- a cause unrelated to the water you’re working
Potential causes of diarrhea on an empty stomach include:
- infections
- IBS
- dumping syndrome
- water intoxication
Here are some potential treatment options for diarrhea.
Home remedies
Home remedies include:
| Cause | Home remedy |
|---|---|
| Sulfate in drinking water | • avoiding water with high levels of sulfate and drinking bottled water |
| Overhydration | • reducing fluid intake • consuming electrolytes |
| IBS | • eating smaller meals • drinking water or fluids after your meal |
| Dumping syndrome | • eating smaller meals more frequently • avoiding liquids for • avoiding dairy and simple sugars |
| Infections | • eating bland foods like: • bananas • rice • applesauce • toast • avoiding alcohol • eating foods high in probiotics |
| Medication side effects | • stopping or changing the dose of certain medications |
Learn more about home remedies for diarrhea.
Medical treatments
Medical treatments include:
| Cause | Treatment |
|---|---|
| Overhydration | • diuretics • sodium replenishment through an IV (intravenous) infusion • stopping medications causing the problem |
| IBS | • anti-diarrheal medications |
| Dumping syndrome | • medications like tolbutamide (Orinase) and propranolol (Hemangeol, Inderal) • surgery |
| Infections | • bismuth subsalicylate (Pepto-Bismol) • antibiotics • antiparasitic medications |
It’s a good idea to seek medical attention if:
- your diarrhea lasts more than 7 days
- your diarrhea is particularly severe
- you notice blood in your stool
- you have stool that’s black or dark
- you’re losing weight
- you have a severe or continuous stomach ache
- you’re unable to keep fluids down
Developing diarrhea after drinking water can be a sign that your water contains sulfate or is contaminated with another substance. Usually, you develop a tolerance to sulfate over a few days, and it’s safe to continue drinking it, as long as levels fall within EPA standards.
If your diarrhea doesn’t go away after a few days, it’s a good idea to see your doctor.
