Gastroesophageal Reflux Disease • affecting the upper gastrointestinal tract. • 10% of the population experience • Heartburn is the cardinal symptom of GERD • Barrett’s esophagus is a variant of GERD in which normal squamous epithelium is replaced by columnar epithelium.
Medical Management • H2 receptor antagonists:Cimetidine , Ranitidine, Famotidine • Proton pump inhibitors (PPIs) such as omeprazole and lansoprazole, Pantoprazole, Rabeprazole
Stomach secretion • The stomach secretes acid, mucus, pepsinogen, and intrinsic factor. • The secreted hydrochloric acid is essential for killing swallowed bacteria while the mucus helps coat and lubricate the stomach’s lining epithelium in order to propel the ingested contents through the digestive system. Pepsinogen is aproteolytic enzyme that helps digest protein and intrinsic factor, a glycoprotein that permits the adequate absorption of dietary vitamin B12.
Peptic Ulcer Disease • Peptic ulcer disease is a common benign (nonmalignant) ulceration of the epithelial lining of the stomach (gastric ulcer) or duodenum (duodenal ulcer) • A complex relationship exits between host defense mechanisms, the presence of elevated acid, pepsin levels, and H. pylori.
Medical Management • (1) sedatives to reduce mental stress if anxiety is thought to be etiologic • (2) antacids to neutralize acid • (3) drugs that act by covering and protecting the ulcer • (4) anticholinergic drugs to decrease the production of acid by the gastric mucosa • (5) histamine H2 receptor antagonists (cimetidine, famotidine, nizatidine, or ranitidine), which block the action of histamine on the gastric parietal cells, thus reducing food-stimulated acid secretion up to 75% • (6) omeprazole, which also suppresses gastric acid secretion but which has a different mechanism of action from that of anticholinergics or H2 receptor antagonists
Ulcerative Colitis • The inflammation in ulcerative colitis may affect all or part of the large intestine. • The hallmark of ulcerative colitis is rectal bleeding and diarrhea. • Patients usually complain of pain that is in both abdominal quadrants. • Anemia is commonly associated with ulcerative colitis. It is most likely caused by blood loss and is typically a microcytic hypochromic anemia of iron deficiency.
Crohn’s Disease • Crohn’s disease is an inflammatory disease of the small or large intestine. The inflammation involves all the layers of the gut. • The clinical presentation of Crohn’s disease depends on the extent of inflammation and on the site of intestinal involvement. • Inflammation of the small intestine may impair its absorption of vital nutrients. Calcium, iron, and folateare absorbed in the duodenum, and their decreased absorption due to inflammation can lead to deficiencies. • Inflammation of the small or large intestines may impair the absorption of fat, fat-soluble vitamins, salt,water, protein, and iron,bilesalts and vitamin B12.
Antibiotic-Induced Diarrhea andPseudomembranous Enterocolitis • In patients who are receiving antibiotic therapy, diarrhea may occur as a result of an alteration of the colonic flora.C. difficile to proliferate and produce a cytopathic toxin. • this condition is mild and subsides when antibiotic therapy is discontinued. • More cases occur when the drug is given orally than when it is administered parenterally. • Clindamycin, ampicillin, and the cephalosporinsare most commonly associated with antibiotic-associated pseudomembranous colitis, but virtually any antibiotic may produce this disorder.
Pseudomembranous Enterocolitis • It is a life-threatening disease • individuals must be treated aggressively with fluids and electrolyte replacement. • Vancomycin, given orally in dosages • of 125 to 500 mg four times daily for 10 to 14 days, is effective in eliminating C. difficile infection. • Metronidazole, in doses of 250 to 500 mg three times daily, is also effective and is less expensive.
Peutz-Jeghers syndrome • is characterized by multiple intestinal polyps throughout the gastrointestinal tract but primarily in the small intestine. • Malignancies in the gastrointestinal tract and elsewhere in the body have been reported in approximately 10% of patients with this syndrome. • Pigmentation(present from birth) of the face, lips, and oral cavity is a hallmark of this syndrome. • facial pigmentation fades later in life, although the intraoral mucosal pigmentation persists. No specific oral treatment is necessary.