Differential Diagnosis of Diarrhea in Children

Children may present with diarrhea which is defined as the passage of loose stools. It is a very common complaint and a list of differential diagnosis should be kept in mind while dealing with a child presenting with this problem.

1. Infection

Viral: Usually resolves in a few days and can be treated symptomatically. Rotavirus, adenovirus and Norwalk virus are more common.

Bacterial: Shigella, salmonella, Campylobacter, E coli , Vibrio, Clostridium species are commonly involved. Spectrum of illness may range from asymptomatic to life threatening. Staph aureus and C perfringens are often associated with food poisoning. Enterohemorrhagic E coli causes bloody diarrhea and may be associated with hemolytic uremic syndrome.

Parasitic: Giardia is often contracted by drinking contaminated water and can cause abdominal distension, diarrhea and at times failure to thrive. Giardia is easily passed through fecal oral route and is common in day care centers. Entamoeba histolytica produces severe coilitis.

2.Postinfectious State
Several viruses can cause severe enteritis resulting in prolonged intestinal mucosal damage, acquired carbohydrate intolerance and malabsorption in infants.

3. Drugs

Antibiotics: Can alter bowel flora and cause loose watery stools. Broad spectrum antibiotics like clindamycin can lead to induction of C difficle overgrowth leading to pseudomembranous colitis.

Laxatives:

Antacids: Magnesium containing antacids can cause osmotic diarrhea.

Cholinergic agents: Metoclopramide and bethenacol are frequently used in children with GERD and may cause significant diarrhea.

Chemotherapy: Mucositis and enteritis can follow radiation and chemotherapy.

4. Diet

• Overfeeding
• Adverse reaction or allergy to some food items
• Excessive intake of High carbohydrate fluids
• Malnutrition

5. Chronic non specific Diarrhea ( Toddler’s Diarrhea )
Typically occurs in children aged 1-3 years. Children appear healthy and continue to grow and develop normally. Excessive fluid intake and an unbalanced diet that consists mostly of low-residue and high carbohydrate may play a role.

6. Lactose Intolerance
It is a frequent cause of chronic diarrhea in pediatric patients. Often associated with bloating and flatulence. Milk or milk products exacerbate the diarrhea.

7. Encopresis or Fecal impaction
In the toddler or older child, encoperesis often presents as diarrhea and is almost always caused by severe constipation.

8. Inflammatory diseases

Inflammatory bowel disease: presentation is quite variable and a child may present with growth failure. diarrhea and abdominal pain

Milk protein allergy: is a pathologic immune reaction induced by milk protein aantigens.

Necrotizing enterocolitis: occurs in premature infants.

9. Malabsorption

Pancreatic dysfunction: leads to fat malabsorption with large greasy foul smelling stools. causes include cystic fibrosis and chronic pancreatitis.

Bacterial overgrowth: consider in postsurgical patients . Leads to bile salt deconjugation which typically promotes watery diarrhea.

Celiac disease: Allergic to gluten in the diet characterized by proximal small bowel mucosal damage and subsequent malabsorption.

10. Irritabe bowel Syndrome
Intermittent diarrhea may alternate with constipation. Symptoms are aggravated by stress. Findings are normal on examination.

11. Other rare causes

• Anatomical abnormalities like short bowel
• Endocrine disorders like hyperthyriodism or diabetes
• Immunodeficiency states
• Tumors
• Inborn errors of metabolism