Dietary Management of Diarrhea
Resume a normal, age-appropriate diet immediately after rehydration is complete, focusing on starches, cereals, yogurt, fruits, and vegetables while strictly avoiding foods high in simple sugars and fats. 1
Immediate Dietary Approach
Continue regular feeding throughout the diarrheal episode without unnecessary dietary restrictions. Early refeeding improves nutritional outcomes, decreases intestinal permeability, and reduces illness duration. 1, 2
Foods to Actively Recommend
- Starches and complex carbohydrates: Rice, potatoes, noodles, crackers, bananas, and bread 1, 2
- Cereals: Rice, wheat, and oat cereals (unsweetened) 1, 2
- Proteins: Soup, yogurt, and age-appropriate protein sources 1, 2
- Fruits and vegetables: Fresh fruits and cooked vegetables 1, 2
Foods to Strictly Avoid
- High simple sugar foods: Soft drinks, undiluted apple juice, Jell-O, presweetened cereals, and candy—these worsen diarrhea through osmotic effects 1, 2
- High-fat foods: Fried foods, fatty meats, and rich desserts—these delay gastric emptying and are poorly tolerated 1, 2
- Irritants: Spicy foods (chili), coffee, and alcohol—these increase gastrointestinal motility and worsen symptoms 1
Age-Specific Recommendations
Infants (Breastfed)
Continue breastfeeding on demand without interruption. Breast milk reduces stool output compared to oral rehydration solution alone and provides optimal nutrition. 1, 2, 3
Infants (Formula-Fed)
Resume full-strength, lactose-free or lactose-reduced formula immediately after rehydration. Do not dilute formula or delay full-strength feeding, as this worsens nutritional outcomes and prolongs diarrhea. 1, 2, 3
If lactose-free formulas are unavailable, full-strength lactose-containing formulas can be used under supervision, but watch for exacerbation of diarrhea. 1
Older Children and Adults
Resume the usual age-appropriate diet during or immediately after rehydration. Emphasize starches, cereals, and complex carbohydrates. 1, 2
Lactose Management
Do not routinely eliminate lactose unless true lactose intolerance is clinically evident. Lactose intolerance is diagnosed by worsening diarrhea upon reintroduction of lactose-containing foods, not by stool pH or reducing substances alone. 1, 2, 3
- Yogurt and firm cheeses are generally well-tolerated even in lactose malabsorption and can be continued 1
- Temporary lactose reduction may be reasonable in patients with chemotherapy-induced diarrhea or clear clinical worsening with lactose 1
- Most people with lactose malabsorption tolerate up to 12g of lactose, so lactose-containing medications rarely cause symptoms 1
Fiber Considerations
Reduce insoluble fiber intake during acute diarrhea. Insoluble fiber may worsen symptoms, though soluble fiber and fiber-enriched formulas can be beneficial in specific contexts like enteral feeding. 1, 4
Critical Pitfalls to Avoid
The BRAT Diet Trap
Do not use the BRAT diet (bananas, rice, applesauce, toast) exclusively or for prolonged periods. While these foods are safe, the BRAT diet provides inadequate energy and protein for recovery. 2
Unnecessary Food Restrictions
Do not instruct patients to avoid solid food for 24 hours. This outdated practice delays nutritional recovery without benefit. 2
Diluting Formula
Never dilute infant formula. This practice worsens nutritional outcomes and prolongs illness duration. 2, 3
Fluid Replacement Alongside Diet
Replace ongoing stool losses with oral rehydration solution (ORS): 10 mL/kg for each watery stool and 2 mL/kg for each episode of vomiting. 1, 3
Maintain adequate hydration (≥1.5 L/day in adults) and separate liquids from solids by 15-30 minutes if dumping syndrome is a concern. 1
Special Populations
Post-Bariatric Surgery Patients
- Avoid refined carbohydrates 1
- Increase protein, fiber, and complex carbohydrates 1
- Separate liquids from solids by ≥30 minutes 1
- Reduce fat and lactose intake 1
Cancer Patients
- Avoid milk and dairy products (except yogurt and firm cheeses) during chemotherapy-induced diarrhea 1
- Limit spices, coffee, and alcohol 1
- Consider highly caloric nutritional supplements with vitamins and minerals for chronic radiation-induced diarrhea 1
Enterally Fed Patients
Consider lower FODMAP formulas and fiber-enriched formulas, as these may reduce diarrhea incidence. 4