The Digestive System: From Basic Sciences to Clinical Practice

Description

This textbook on the digestive system was developed in collaboration with medical students to meet both students' and teachers' needs and objectives. It is currently the official gastroenterology textbook for undergraduate students in all French medical schools in Canada, and is also used in Europe and Africa. An updated and improved 3rd edition was published in French in 2020; this translation and update make the book available in English for the first time. The text features contributions from GI experts from Quebec, France, French Africa, and from key Canadian GI experts. The first part of the book covers the eight main organs of the digestive system, while the second half discusses the major clinical diseases and symptoms that affect the digestive system. This book is comprehensive and well-organized, and features color-coded and beautifully designed figures and tables that make the book helpful and accessible to students. Preface Acknowledgments Introduction Contents Contributors Abbreviations Warning I: The Digestive Organs 1: The Esophagus 1.1 Macroscopic Anatomy 1.1.1 Shape and Structure 1.1.2 Vascular Supply 1.1.3 Innervation 1.2 Microscopic Anatomy 1.2.1 Esophageal Mucosa 1.2.2 Muscularis 1.2.3 Serosa 1.3 Embryology/Development 1.3.1 Normal Development 1.3.2 Atresias of the Esophagus 1.3.3 Esophageal Stenosis/Strictures 1.3.4 Duplications and Cysts 1.3.5 Rings and Webs 1.4 Secretion/Absorption 1.5 Motility/Sensitivity 1.5.1 Oropharyngeal (Transfer) Motility 1.5.2 Esophageal (Transport) Motility 1.5.3 Sphincters: Upper and Lower 1.5.4 Sensory Function 1.6 Inflammation Disorders 1.6.1 Peptic Esophagitis 1.6.2 Infectious Esophagitis 1.6.3 Eosinophilic Esophagitis 1.6.4 Caustic Esophagitis 1.6.5 Drug-Induced Esophagitis 1.6.6 Radiation Esophagitis 1.7 Tumor Disorders 1.7.1 Types of Esophageal Neoplasia 1.7.2 Clinical 1.7.3 Diagnosis of Esophageal Cancer 1.7.4 Treatment of Esophageal Cancer 1.8 Function Disorders 1.8.1 Gastroesophageal Reflux Disease (GERD) 1.8.2 Oropharyngeal (Transfer) Dysmotility 1.8.3 Esophageal (Transport) Dysmotility 1.8.4 Sensitivity Disorders 1.9 Miscellaneous 1.9.1 Hiatal Hernia 1.9.2 Diverticulum 1.9.3 Esophageal Rupture 1.9.4 Esophageal Bleeding 1.9.5 Mallory-Weiss 1.9.6 Schatzki’s Ring 2: The Stomach 2.1 Macroscopic Anatomy 2.1.1 Shape and Structure 2.1.2 Vascular Supply 2.1.3 Innervation 2.2 Microscopic Anatomy 2.3 Embryology 2.3.1 Development 2.3.2 Developmental Abnormalities 2.4 Absorption/Secretion 2.4.1 Absorption 2.4.2 Secretion/HCl, Pepsin, and Intrinsic Factor 2.4.2.1 Parietal Cell 2.4.2.2 Chief Cell 2.4.2.3 Mucous Cell 2.4.2.4 Endocrine Cells 2.4.3 Regulation of Gastric Acid Secretion 2.5 Motility/Sensitivity 2.5.1 Motility of the Stomach 2.5.2 Sensitivity of the Stomach 2.6 Inflammation Disorders 2.6.1 Peptic Ulcer Disease 2.6.2 Gastritis and Gastropathies 2.7 Tumor Disorders 2.7.1 Adenocarcinoma 2.7.2 Lymphoma 2.7.3 Neuroendocrine Tumors (NET) 2.7.4 Stromal Tumors 2.7.5 Polyps 2.8 Function Disorders 2.8.1 Motor Disorders 2.8.1.1 Hypomotility/Gastroparesis 2.8.1.2 Hypermotility Disorders 2.8.2 Sensory Disorders/Functional Dyspepsia 2.8.3 Cyclic Vomiting Syndrome 2.8.4 Aerophagia/Belching/Excessive Belching Syndrome 2.8.5 Rumination Syndrome Table 2.2 Ulceration in stomach or duodenum: causes Table 2.3 Peptic ulcer: acute complications and their treatments Table 2.7 H. pylori eradication: indications and benefits Table 2.8 NSAID/ASA ulcers: therapeutic strategies Table 2.9 PPIs: potential side effects Table 2.10 Gastritis and gastropathies Table 2.11 Gastroparesis: causes Table 2.12 Functional dyspepsia: therapeutic options 2.9 Miscellaneous 2.9.1 Gastrinoma (Zollinger-Ellison Syndrome) 2.9.2 Ménétrier’s Hypertrophic Gastritis 2.9.3 Volvulus 2.9.4 Bezoars 2.9.5 Perforations 2.9.6 Gastric Bleeding 2.9.7 Dieulafoy’s Lesion 2.9.8 Gastric Surgery 3: The Small Intestine 3.1 Macroscopic Anatomy 3.1.1 Shape and Structure 3.1.2 Vascular Supply 3.1.3 Innervation 3.2 Microscopic Anatomy 3.2.1 Mucosa 3.2.2 Submucosa 3.2.3 Muscularis 3.2.4 Serosa 3.2.5 Summary 3.3 Embryology/Developmental Abnormalities 3.4 Absorption/Secretion 3.4.1 Absorption by the Small Intestine 3.4.1.1 General Mechanisms 3.4.1.2 Water and Electrolyte Uptake 3.4.1.3 Absorption of Macronutrients 3.4.1.4 Vitamin Absorption 3.4.1.5 Mineral Absorption 3.4.1.6 Distal Small Intestine 3.4.1.7 Vitamin B12 Absorption 3.4.1.8 Bile Salt Absorption 3.4.1.9 Drug Absorption/Biotransformation 3.4.2 Secretion by the Small Intestine 3.4.2.1 Water and Electrolyte Secretion 3.4.2.2 Bicarbonate Secretion 3.4.2.3 Mucus Secretion 3.4.2.4 “Endocrine” Secretions 3.4.2.5 Chloride Secretion and Pathological Conditions 3.4.2.6 Miscellaneous 3.4.3 Other Functions of the Small Intestine 3.4.3.1 Protection 3.4.3.2 Digestive Regulation 3.5 Motor/Sensory Functions 3.5.1 Intestinal Muscle 3.5.2 Peristaltic Reflex 3.5.3 Enteric Nervous System 3.5.4 Interdigestive Motility/MMC 3.5.5 Postprandial or Digestive Motility 3.5.6 Sensitivity 3.6 Inflammation Disorders 3.6.1 Celiac Disease/Gluten Enteropathy 3.6.2 Crohn’s Disease 3.6.3 Infections 3.6.4 “Special” Infections of the Small Intestine 3.6.5 Small Intestinal Bacterial Overgrowth (SIBO) Table 3.8 Crohn’s disease diarrhea = multifactorial and often related to the length and severity of intestinal inflammation and of concomitant colon involve ment Table 3.10 Traveler’s diarrhea Table 3.11 Stool examination for pathogens 3.7 Tumor Disorders 3.7.1 Malignant and Benign Tumors 3.7.2 Neuroendocrine Tumors (NETs) 3.8 Function Disorders 3.8.1 Intestinal Pseudo-obstruction 3.8.2 Rapid Transit 3.8.3 Slow Transit/Ileus 3.8.4 Irritable Bowel Syndrome (IBS) Table 3.14 Small intestine: transit variations 3.9 Miscellaneous 3.9.1 Ulcerations 3.9.2 Vascular Abnormalities (Angiectasias, Etc.) 3.9.3 Intestinal Ischemia 3.9.4 Bile Salt Diarrhea 3.9.5 Lactose Intolerance 3.9.6 Meckel’s Diverticulum 3.9.7 Short Bowel Syndrome/Intestinal Failure 3.9.8 Congenital Diarrhea 3.9.9 Diarrhea in Children 4: The Colon 4.1 Macroscopic Anatomy 4.1.1 Shape and Structure 4.1.2 Vascular Supply 4.1.3 Innervation 4.2 Microscopic Anatomy 4.2.1 Mucosa 4.2.2 Muscularis 4.2.3 Serosa 4.3 Embryology/Development 4.4 Absorption/Secretion 4.4.1 Water Absorption 4.4.2 Sodium Absorption 4.4.3 Potassium Movements 4.4.4 Chloride Movements 4.4.5 Nutrient Uptake 4.4.6 Secretions 4.4.7 Intestinal Flora (Microbiota) 4.4.8 Intestinal Gas 4.4.9 Summary 4.5 Motility/Sensitivity 4.5.1 Motility 4.5.2 Sensitivity 4.6 Inflammation Disorders 4.6.1 Infectious Colitis Table 4.1 Management of Clostridioides difficile infection 4.6.2 Ischemic Colitis and Colonic Ischemia 4.6.3 Microscopic Colitis 4.6.4 Radiation Colitis 4.6.5 Colitis in Oncology 4.6.6 Inflammatory Bowel Diseases (IBD): Ulcerative Colitis and Crohn’s Disease 4.7 Tumor Disorders 4.7.1 Benign Neoplasms: Polyps 4.7.2 Malignant Neoplasm: Adenocarcinoma 4.7.3 Other Colon Tumors 4.7.4 Tropical Specificity 4.8 Function Disorders 4.8.1 Irritable Bowel Syndrome (IBS) 4.8.2 Colon Transit Disorders Table 4.16 Rapid colon transit: causes Table 4.17 Slow colon transit: causes 4.8.3 Bile Acid Diarrhea 4.9 Miscellaneous 4.9.1 Diverticular Disease Table 4.18 Medical treatment of diverticulitis 4.9.2 Acute Appendicitis 4.9.3 Colonic Bleeding Table 4.20 Management of lower GI bleeding 4.9.4 Epiploic Appendix/Appendagitis 4.9.5 Volvulus 4.9.6 Melanosis Coli 4.9.7 Bristol Stool Chart 5: The Pancreas 5.1 Macroscopic Anatomy 5.1.1 Shape and Structure 5.1.2 Vascular Supply 5.1.3 Innervation 5.2 Microscopic Anatomy 5.2.1 Acini 5.2.2 Ducts 5.2.3 Islets of Langerhans 5.3 Embryology 5.3.1 Normal Development 5.3.2 Developmental Abnormalities 5.4 Secretion 5.4.1 Acinar Cell 5.4.2 Ductal Cell 5.4.3 Regulation of Pancreatic Secretion 5.4.4 Activation of Pancreatic Proenzymes 5.5 Motility/Sensitivity 5.6 Inflammation Disorders 5.6.1 Acute Pancreatitis 5.6.2 Chronic Pancreatitis 5.7 Tumor Disorders . Table 5.8 Primary tumors of the exocrine pancreas according to the World Health Organization 5.7.1 Pancreatic Cancer/Adenocarcinoma 5.7.2 Cystic Tumors/Cysts 5.7.3 Neuroendocrine Tumors (NETs) 5.8 Function Disorders 5.9 Miscellaneous 5.9.1 Cystic Fibrosis 6: The Biliary Tree 6.1 Macroscopic Anatomy 6.1.1 Shape and Structure 6.1.2 Vascular Supply 6.1.3 Innervation 6.2 Microscopic Anatomy 6.2.1 Bile Ducts 6.2.2 Gallbladder 6.3 Embryology 6.3.1 Normal Development 6.3.2 Developmental Malformations 6.4 Secretion/Absorption 6.4.1 General Considerations 6.4.2 Bile 6.4.3 Bile Acids and Bile Salts 6.4.4 Bilirubin/Icterus 6.4.5 Solubility of Bile Constituents/Biliary Stones 6.5 Motility/Sensitivity 6.6 Inflammation Disorders 6.6.1 Cholecystitis/Lithiasis 6.6.2 Cholangitis 6.6.3 Primary Sclerosing Cholangitis 6.6.4 Autoimmune Cholangitis 6.6.5 “Atypical” Infectious Cholangitis Table 6.3 Treatment of gallstone(s) disease 6.7 Tumor Disorders 6.7.1 Cholangiocarcinoma 6.7.2 Gallbladder Cancer 6.7.3 Benign Tumors/Polyps 6.8 Function Disorders 6.8.1 Functional Gallbladder Disorders 6.8.2 Functional Oddi Disorders 6.9 Miscellaneous 6.9.1 Chronic Cholecystitis 6.9.2 Porcelain Gallbladder 6.9.3 Acute Acalculous Cholecystitis 6.9.4 Emphysematous Cholecystitis 6.9.5 Mirizzi’s Syndrome 6.9.6 Isolated Bile Duct Dilatation 6.9.7 Adenomyomatosis-Cholesterolosis 7: The Anorectum 7.1 Macroscopic Anatomy 7.1.1 Rectum and Anus 7.1.2 Vascular Supply 7.1.3 Innervation 7.2 Microscopic Anatomy 7.2.1 Mucosa 7.2.2 Muscularis 7.2.3 Serosa 7.3 Embryology 7.3.1 Normal Development 7.3.2 Atresias 7.3.3 Hirschsprung’s Disease 7.4 Secretion/Absorption 7.5 Motility/Sensitivity 7.5.1 Anorectal Physiology 7.5.2 Defecation 7.6 Inflammation Disorders 7.6.1 Rectal Inflammation (Proctitis, Rectal Ulcers) 7.6.2 Anal and Perineal Inflammation (Abscess, Fistulas, Anal Pruritus) 7.7 Tumor Disorders 7.7.1 Rectum Cancer 7.7.2 Anus Cancer 7.8 Function Disorders 7.8.1 Proctalgia Fugax 7.8.2 Levator Ani Syndrome 7.8.3 Anorectal Dyssynergia/Anismus 7.8.4 Hirschsprung’s Disease 7.8.5 Fecal Incontinence 7.9 Miscellaneous 7.9.1 Vascular Diseases: Hemorrhoids/Varices 7.9.2 Anal fissure 7.9.3 Neurological Diseases with Anorectal Impact 7.9.4 Pelvic Floor Disorders 7.9.5 Fecaloma 8: The Liver 8.1 Macroscopic Anatomy 8.1.1 Shape and Structure 8.1.2 Vascular Supply 8.1.3 Innervation 8.2 Microscopic Anatomy 8.2.1 Organization of Hepatocytes: Lobules and Acini 8.2.2 Sinusoids 8.2.3 Bile Ducts 8.2.4 Hepatocytes 8.2.5 Kupffer Cells 8.2.6 Hepatic Stellate Cells 8.2.7 Liver-Associated Lymphocytes (LAL) 8.3 Embryology/Development 8.4 Hepatic Catabolism 8.4.1 Heme-Bilirubin 8.4.2 Urea-NH4+ 8.4.3 Drugs 8.4.4 Hormones 8.4.5 Lactic Acid 8.5 Hepatic Synthesis 8.5.1 Proteins 8.5.2 Hormones and Pro-hormones 8.5.3 Bile Salts 8.5.4 Cholesterol 8.5.5 Glucose, Lipids, and Amino Acids 8.6 Inflammation Disorders 8.6.1 Acute Hepatitis 8.6.1.1 Viral Hepatitis (A, B, C, D, E, and Other Viruses) 8.6.1.2 Toxic Hepatitis (Drugs, Acetaminophen) 8.6.1.3 Autoimmune/Metabolic Hepatitis 8.6.1.4 Vascular Hepatitis Table 8.4 Acute hepatitis: paraclinical evaluation 8.6.2 Chronic Hepatitis 8.6.2.1 Viral Hepatitis (B, D, C, E) 8.6.2.2 Toxic Alcoholic Hepatitis 8.6.2.3 Chronic Autoimmune Liver Diseases (AIH, PBC, Sclerosing Cholangitis) 8.6.2.4 Metabolic Liver Diseases (NAFLD, Hemochromatosis, Wilson’s) 8.6.3 Cirrhosis 8.6.3.1 Pathology 8.6.3.2 Etiology of Cirrhosis Table 8.7 Causes of cirrhosis 8.6.3.3 Clinical Manifestations of Cirrhosis Table 8.8 Clinical signs suggestive of cirrhosis Table 8.9 Classification of portal hypertension Table 8.10 Treatment of variceal bleeding in  cirrhotic patients Table 8.11 Treatment of ascites Table 8.13 Treatment of hepatic encephalopathy 8.6.3.4 Prognosis of Cirrhosis 8.7 Tumor Disorders 8.7.1 Primary Neoplasms 8.7.2 Secondary Neoplasms 8.7.3 Benign Tumors 8.7.4 Other Lesions (Cysts, Abscesses) 8.8 Function Disorders 8.8.1 Porphyria 8.8.2 Disorders of the Urea Cycle 8.8.3 Glycogen Storage Diseases 8.8.4 Tyrosinemia 8.8.5 Galactosemia and Fructosemia 8.8.6 α1-Antitrypsin Deficiency 8.9 Miscellaneous 8.9.1 Liver Transplantation Table 8.16 Contraindications to hepatic transplantation Table 8.17 Liver transplant indications 8.9.2 Pregnancy and Liver II: Digestive Symptoms, Signs and Other 9: Esophageal Symptoms: Heartburn, Dysphagia, and Chest Pain 9.1 Digestive Symptoms 9.1.1 Heartburns 9.1.2 Odynophagia 9.1.3 Dysphagia 9.2 Extra-digestive Symptoms 9.2.1 “Respiratory” Symptoms 9.2.2 “Cardiac” Symptoms 10: Nausea and Vomiting 10.1 Definition 10.2 Physiology 10.3 Causes Table 10.1 Nausea/vomiting: causes 10.4 Complications 10.5 Treatment 11: Upper Gastrointestinal Bleeding (UGIB) 11.1 Definition 11.2 Clinical Presentation 11.3 Causes of UGIB 11.4 Treatment of UGIB Table 11.2 UGIB: initial clinical assessment and emergency management 11.5 Special Topic: GI Bleeding and Altered Coagulation 12: Dyspepsia 12.1 Definition 12.2 Symptoms 12.3 Differential Diagnosis 12.4 Investigation 12.5 Treatment 13: Diarrhea 13.1 Definition 13.2 Simplified Pathophysiology 13.3 Differential Diagnosis Table 13.2 Diarrhea: diagnostic tests 13.4 Treatment 13.5 Summary 14: Abdominal Distension and Bloating 14.1 Abdominal Distension Table 14.1 Abdominal distension: causes 14.2 Abdominal Bloating 14.3 Treatment Table 14.2 Treatment of intestinal gases 15: Constipation 15.1 Definition 15.2 Pathophysiology 15.3 Investigation 15.4 Treatment 15.5 Miscellaneous 15.6 Constipation in Children 16: Abdominal Pain 16.1 General Considerations 16.2 Clinical Approach to Abdominal Pain 16.3 Diagnostic Strategies in Abdominal Pain 16.4 Therapeutic Strategies for Abdominal Pain 16.5 Miscellaneous Table 16.4 Non-visceral/nonsurgical abdominal pain 16.6 Abdominal Pain in Children 17: Abdominal Hernias 17.1 Definition 17.2 Diaphragmatic Hernias 17.3 Ventral Hernias 17.4 Groin Hernias 17.5 Pelvic Hernias 17.6 Flank Hernias 18: Fecal Incontinence 18.1 General Considerations 18.2 Physiology and Pathophysiology 18.3 Investigation 18.4 Treatment Table 18.2 Treatment of incontinent patients 19: Anorectal Pain 19.1 Thrombosed Hemorrhoid 19.2 Acute Anal Fissure 19.3 Perianal Abscess 19.4 Proctalgia Fugax 19.5 Levator Ani Syndrome 20: Rectal Bleeding 20.1 Common Causes of Chronic Intermittent Rectal Bleeding 20.2 Investigation 21: Lower GI Bleeding 21.1 Step One 21.2 Step Two 21.3 Step Three 21.4 Step Four 21.5 Step Five 21.6 Step Six 21.7 Special Topic: GI Bleeding and Altered Coagulation 22: Food Allergies 22.1 IgE-Mediated Manifestations 22.2 Non-IgE-Mediated Manifestations 22.3 Mixed, IgE- and Non-IgE-Mediated Manifestations 23: Undernutrition and Nutritional Support 23.1 Types of Undernutrition 23.2 Pathophysiology of Fasting 23.3 Nutritional Assessment Table 23.2 Nutritional assessment: clues to look for 23.4 Indications for Nutritional Support 23.5 Assessment of Energy and Protein Needs 23.6 Nutritional Support: Enteral Versus Parenteral 23.7 Enteral Nutrition Table 23.4 Gastric or jejunal tube feeding (?) 23.8 Parenteral Nutrition Table 23.7 Parenteral nutrition: evaluation of nutrient solutions to be administered 23.9 Re-feeding Syndrome 23.10 Addendum 24: Obesity 24.1 Definition of Obesity 24.2 Complications of Obesity 24.3 Etiology of Obesity 24.4 Treatment of Obesity 24.5 Summary 25: Genes and Digestive Cancers 25.1 Clinical Approach to Families at Risk 25.2 Predisposition Syndromes to Colorectal Cancer 25.2.1 Lynch Syndrome 25.2.2 Hereditary Polyposis 25.2.2.1 Familial Adenomatous Polyposis (FAP) 25.2.2.2 Hamartomatous Polyposis 25.3 Predisposition to Other Digestive Cancers 25.3.1 Pancreatic Cancer 25.3.2 Hereditary Diffuse Gastric Cancer Table 25.1 When to suspect lynch syndrome? 26: Jaundice 26.1 General Considerations 26.2 Differential Diagnosis 26.2.1 First Question Asked: Is This a Pre-conjugation Disorder? 26.2.2 Second Question: Is the Post-conjugation Disorder Located at the Hepatic or Post-hepatic Level? 26.3 Treatment 27: Abnormal Liver Tests 27.1 Bilirubin Elevation 27.2 Transaminase Elevation Table 27.1 Causes of abnormal blood liver tests in asymptomatic subjects Table 27.4 Some drugs and substances whose abuse can increase transaminases 27.3 Alkaline Phosphatase Elevation 28: Ascites 28.1 Causes 28.2 Diagnosis 28.3 Treatment Table 28.1 Ascites: etiological diagnoses Table 28.2 Ascites fluid analyses (to be performed according to the clinical context) 29: Diets and Digestive Diseases 29.1 Esophageal Disorders 29.1.1 Oropharyngeal Dysphagia 29.1.2 Obstructive Esophageal Dysphagia 29.1.3 Eosinophilic Esophagitis (EoE) 29.1.4 Gastroesophageal Reflux Disease (GERD) 29.2 Gastric Disorders 29.2.1 Gastroparesis 29.2.2 Dyspepsia 29.2.3 Dumping Syndrome 29.2.4 Post-gastrectomy 29.3 Intestinal Disorders 29.3.1 Celiac Disease 29.3.2 Non-celiac Gluten Sensitivity (NCGS) 29.3.3 Lactose Intolerance 29.3.4 Acute Gastroenteritis 29.4 Colon Disorders 29.4.1 Irritable Bowel Syndrome (IBS) 29.4.2 Chronic Constipation 29.4.3 Diarrhea 29.4.4 Bloating 29.4.5 Diverticular Disease 29.4.6 Inflammatory Bowel Disease (IBD) 29.5 Biliopancreatic Disorders 29.5.1 Acute Pancreatitis 29.5.2 Chronic Pancreatitis 29.5.3 Gallstones 29.6 Liver Disorders 29.6.1 Cirrhosis Malnutrition 29.6.2 Ascites 29.6.3 Encephalopathy 29.6.4 NASH 29.6.5 Metabolic Function Disorders Index