GI Topics - Piyush Gupta PG Textbook of Pediatrics (3rd Ed.)

Major GI Topics Covered

• Esophageal atresia and tracheo-esophageal fistula (TEF)
• Hypertrophic pyloric stenosis
• Intestinal atresia and stenosis
• Malrotation and volvulus
• Hirschsprung disease (congenital aganglionic megacolon)
• Anorectal malformations
• Diaphragmatic hernia
• Meckel's diverticulum
• Intussusception

• Esophageal motility disorders (new chapter in 2nd/3rd edition)
• Gastroesophageal reflux disease (GERD)
• Achalasia cardia
• Functional abdominal pain (FAP) and Rome criteria
• Constipation and encopresis
• Irritable bowel syndrome (IBS) in children

• Acute gastroenteritis - etiology, ORS, management
• Persistent diarrhea and chronic diarrhea
• Dysentery
• Typhoid fever (gastro-intestinal presentation)
• Intestinal tuberculosis
• Helicobacter pylori infection
• Necrotizing enterocolitis (NEC) - in neonate
• Inflammatory bowel disease (Crohn's disease, Ulcerative colitis)

• Celiac disease (gluten-sensitive enteropathy)
• Lactose intolerance
• Toddler's diarrhea
• Short bowel syndrome
• Protein-losing enteropathy
• Tropical sprue

• Neonatal cholestasis (biliary atresia, neonatal hepatitis)
• Viral hepatitis (A, B, C, E) in children
• Autoimmune hepatitis
• Wilson's disease
• Metabolic liver diseases
• Portal hypertension and its management
• Cirrhosis in children
• Liver failure/acute liver failure

• Pancreatitis (acute and chronic) in children
• Cystic fibrosis (pancreatic insufficiency)

• Upper and lower GI bleeding approach
• Portal hypertensive bleeding

• Malnutrition and gut
• Microbiome (new chapter)
• Enteral nutrition

Key Features of GI Section in This Book

• India-centric approach with IAP guidelines wherever applicable
• Evidence-based diagnostic recommendations highlighted with color coding
• New 3rd edition addition: Esophageal Motility Disorders and Microbiome as dedicated chapters
• Summary "In a Nutshell" points at end of each chapter

Note: The Piyush Gupta PG Textbook of Pediatrics is not in the available medical library database, so this topic list is compiled from official book descriptions, the book's own website (piyushgupta.org), Amazon listings, and available excerpts. For the exact chapter list with page numbers, refer to the physical/digital book's table of contents - specifically Volume 2 for Systemic GI Disorders and Volume 1 for neonatal GI conditions.

Acute Diarrhea in Children - PG Pediatrics (Piyush Gupta Style)

Definition

• Acute diarrhea: ≥3 loose/watery stools per 24 hours lasting <14 days
• Persistent diarrhea: 14-29 days
• Chronic diarrhea: ≥30 days
• Global burden: >500,000 deaths/year in children <5 years

Etiology

Viral (most common overall)

Bacterial

Parasitic

• Giardia lamblia - frothy, foul-smelling, fatty stools
• Entamoeba histolytica - dysentery with flask-shaped ulcers; liver abscess risk
• Cryptosporidium - watery; severe in immunocompromised

Other Causes

• Food allergies / food poisoning
• Medications (antibiotics → secondary lactase deficiency)
• Initial presentation of chronic diarrhea

Pathophysiology / Mechanisms

Clinical Assessment

History

• Duration, frequency, character of stools (watery/bloody/mucoid)
• Vomiting, fever
• Urine output (number of wet diapers)
• Recent travel, antibiotic use, sick contacts, food intake

Signs of Dehydration (assess severity)

• Ill/toxic appearance
• Sunken eyes
• Dry mucous membranes
• Decreased tears
• Decreased skin turgor
• Abnormal respiration

Indications for Medical Evaluation (Red Flags)

• Age <6 months or weight <8 kg
• Premature birth, chronic conditions
• Fever ≥38°C in infants <3 months, or ≥39°C in ages 3-36 months
• Visible blood or mucus in stool
• High-output frequent diarrhea
• Persistent vomiting
• Sunken eyes, decreased tears, dry mucosa, decreased urine output
• Change in mental status (irritability, lethargy)
• Failure of home ORS trial

Management

WHO Treatment Plans

• Continue breastfeeding
• Extra ORS after each loose stool: <2 yrs → 50-100 mL; >2 yrs → 100-200 mL
• Zinc: 10 mg/day (<6 months); 20 mg/day (≥6 months) for 14 days
• Return if signs worsen

• ORS 75 mL/kg over 4 hours (supervised)
• Reassess every hour
• If tolerating → continue Plan A

• IV fluids: Ringer's Lactate (preferred) or Normal Saline
  • <1 year: 30 mL/kg over 1 hour + 70 mL/kg over 5 hours
  • ≥1 year: 30 mL/kg over 30 min + 70 mL/kg over 2.5 hours
• Reassess every 15-30 min

WHO-ORS Composition (Reduced Osmolarity)

Reduced osmolarity ORS (245 mOsm/L) is preferred over old formulation (311 mOsm/L) - fewer episodes of vomiting, less stool output.

Zinc Supplementation

• Decreases duration and severity of diarrhea
• Reduces incidence of future diarrhea by 25%
• Dose: 10 mg/day (<6 months); 20 mg/day (≥6 months) for 14 days
• Greater benefit in malnourished children

Antibiotic Therapy

Antibiotics NOT needed for viral gastroenteritis or most uncomplicated bacterial AGE.

Diet

• Continue breastfeeding throughout illness
• Resume normal feeding immediately after rehydration (do NOT fast)
• Avoid high-sugar drinks (fruit juices worsen diarrhea by osmotic effect)
• BRAT diet (Banana, Rice, Applesauce, Toast) historically used but not mandatory
• Avoid dairy temporarily in non-breastfed infants (secondary lactase deficiency)

Antidiarrheal Drugs in Children

• Loperamide: NOT recommended in children <2 years; risk of ileus and toxicity
• Avoid in dysentery or suspected STEC (risk of toxic megacolon + HUS)
• Ondansetron (antiemetic): can facilitate ORS administration; short-term use acceptable

Investigations

• Not needed for uncomplicated acute diarrhea
• Stool culture: if blood/mucus in stool, systemic involvement, immunocompromised, illness >2 weeks
• Test for E. coli O157:H7 separately (not in routine stool culture)
• ELISA/antigen test: for Rotavirus, Giardia, Cryptosporidium
• CBC, electrolytes, BUN/creatinine: if moderate-severe dehydration or suspected complications
• Stool for ova and parasites: travel history

Complications

• Dehydration and electrolyte imbalance (hyper/hyponatremia)
• HUS (STEC O157:H7): triad of microangiopathic hemolytic anemia + thrombocytopenia + acute kidney injury
• Intussusception: post-rotavirus vaccination, or complicating gastroenteritis
• Toxic megacolon (C. difficile, STEC - especially if antidiarrheals given)
• Reactive arthritis (Salmonella, Campylobacter, Yersinia, Shigella)
• Guillain-Barre syndrome (Campylobacter)
• Secondary lactase deficiency → prolonged diarrhea
• Persistent diarrhea / malnutrition cycle

Prevention

• Rotavirus vaccine: RotaTeq (3 doses: 2, 4, 6 months) or Rotarix (2 doses: 2, 4 months)
• Exclusive breastfeeding for 6 months
• Safe drinking water and food hygiene
• Handwashing: reduces diarrheal disease by ~30%
• Zinc supplementation in malnourished children

Sources: Tintinalli's Emergency Medicine; Rosen's Emergency Medicine; Symptom to Diagnosis (4th ed.) - all confirmed the same management principles aligned with WHO/AAP/ESPGHAN guidelines.