What are the potential causes of daily vomiting and diarrhea?

Potential Causes of Daily Vomiting and Diarrhea

Daily vomiting and diarrhea most commonly result from infectious gastroenteritis, but chronic symptoms require systematic evaluation for gastrointestinal obstruction, malabsorption disorders, endocrine dysfunction, medications, and dietary factors. 1

Age-Specific Considerations

In Infants

• Viral gastroenteritis is the most common cause, presenting with sudden onset vomiting, mild fever, diarrhea, and relatively short duration 1
• Gastroesophageal reflux (GER) causes nonbilious vomiting/regurgitation, particularly in the first weeks of life, often related to overfeeding; infants with normal weight gain typically do not have obstruction 1
• Bilious emesis or forceful vomiting requires urgent evaluation for gastrointestinal obstruction including malrotation with volvulus, hypertrophic pyloric stenosis, or intussusception 1
• Systemic infections (sepsis, enteritis, pneumonia, otitis media, meningitis) and metabolic disorders (diabetes, adrenocortical hyperplasia) must be considered 1

In Adults

• Infectious gastroenteritis from viral agents (rotavirus, norovirus, adenovirus, astrovirus) or bacterial pathogens remains the leading acute cause 2, 3, 4
• Clostridium difficile infection should be suspected with recent antibiotic use 1

Systematic Diagnostic Approach

Critical History Elements

• Duration and pattern: Symptoms <3 months, nocturnal diarrhea, or continuous symptoms suggest organic disease 1
• Medication review: Up to 4% of chronic diarrhea cases are medication-induced, particularly from magnesium supplements, ACE inhibitors, NSAIDs, gliptins, antibiotics, and antiarrhythmics 1
• Dietary factors: Excessive caffeine, lactose in lactase-deficient patients, sugar-free sweeteners (sorbitol), and FODMAPs can cause symptoms 1, 5
• Alcohol abuse: Causes diarrhea through direct epithelial toxicity, rapid transit, decreased disaccharidase activity, and pancreatic dysfunction 1
• Previous surgery: Ileal or right colon resections lead to malabsorption, bile acid diarrhea, or bacterial overgrowth 1

Malabsorption Disorders

• Celiac disease has a prevalence of 0.5-1% in Western populations and commonly presents with chronic diarrhea; serological testing should be routine 1
• Bile acid malabsorption has higher prevalence in diabetics and typically occurs after meals, responding to bile acid sequestrants like cholestyramine 1, 5
• Lactose intolerance contributes to chronic diarrhea, particularly in diabetic patients 5
• Pancreatic insufficiency from chronic pancreatitis, pancreatic carcinoma, or cystic fibrosis causes malabsorptive diarrhea 1

Endocrine and Systemic Causes

• Hyperthyroidism causes diarrhea through endocrine effects on gut motility 1
• Diabetes mellitus predisposes to diarrhea via autonomic neuropathy, bacterial overgrowth, bile acid malabsorption, and medication effects 1, 5
• Addison's disease and hypoparathyroidism can present with chronic diarrhea 1
• Hormone-secreting tumors (VIPoma, gastrinoma, carcinoid) cause secretory diarrhea 1

Inflammatory and Structural Causes

• Inflammatory bowel disease should be suspected with alarm features: bloody stools, weight loss, anemia, elevated inflammatory markers 1
• Small bowel bacterial overgrowth occurs with surgical bypass procedures, systemic sclerosis, or diabetes 1
• Mesenteric ischemia and radiation enteritis cause chronic symptoms 1

Initial Laboratory Evaluation

Basic screening tests identify organic disease with high specificity: 1

• Complete blood count (anemia, particularly iron deficiency, suggests small bowel enteropathy)
• ESR and CRP (elevated in inflammatory conditions)
• Comprehensive metabolic panel (electrolytes, liver function, albumin)
• Thyroid function tests (suppressed TSH predicts hyperthyroidism)
• Vitamin B12, folate, calcium, ferritin
• Serological testing for celiac disease (tissue transglutaminase antibodies or antiendomysium antibodies) 1

Common Pitfalls to Avoid

• Do not dismiss medication-induced diarrhea: Systematically review all medications, supplements, and dietary additives 1
• Do not overlook diabetic patients: They have increased risk for bile acid malabsorption, lactose intolerance, and sorbitol-induced diarrhea from sugar-free products 5
• Do not miss Clostridium difficile: Test any patient with recent antibiotic exposure 1
• Do not assume functional disease without testing: Celiac disease and other organic causes frequently present with subtle symptoms 1