git disorders
TRANSCRIPT
Ulceroinflammatory Disorders of the GIT
Dr. Mehzabin Ahmed
TOPICS Common symptoms & terminology Disorders of :
Mouth: Ulcers, Premalignant lesions Pharynx: Infections, Tumors Salivary gland: Inflammations, Tumors Esophagus: Hiatus hernias, Barrett esophagus Stomach: Peptic ulcers Intestines: Inflammatory bowel disease (Crohn
disease & ulcerative colitis) and Malabsorption syndromes
The gastrointestinal tract extends from the mouth to the
anus and includes the oral cavity and salivary glands,
pharynx, oesophagus, stomach, small and the large
intestines.
The main function of the GIT is digestion, absorption
and assimilation of the food consumed.
1. Dysphagia: Difficulty in swallowing.
Causes : Acute infections of the pharynx or tonsils, or Obstruction by foreign bodies or tumors (in the oesophagus or outside
it producing compression) or Impaired neuromuscular function (as in achalasia cardia or multiple
sclerosis)
2. Leukoplakia: is a term used to describe the white patches of keratosis (increased keratinization) resulting due a chronic irritation. It is characterized by Hyperkeratinization and hyperplasia of the squamous epithelium Dysplasia in some cases and in these situations it is premalignant.
3. Heart burn: burning pain in the epigastric region due to: Irritation of the oesophageal or the gastric mucosa, usually with
inflammation and ulceration (peptic ulcers, reflux esophagitis).
4. Abdominal pain: it can originate in the a) Viscera: due to spasm or colic of the muscular layer of the gut b) Peritoneum: due to irritation or inflammation5. Blood loss: it may be asa) Hematemesis: Vomiting of blood- usually due to an upper GI
bleeding, due to: Oesophagus: ruptured blood vessels (oesophageal varices) r Stomach: due to
an erosion by an ulcer Mallory Weis syndrome (oesophageal mucosal tears in chronic
alcoholic occurring due to retching and vomiting b) Melena: passage of altered blood in the stools.
the blood lost may originate from - Upper GI:. It occurs in ulcers and tumors of the stomach and
duodenum- Lower GI: the blood in the stools appears fresh and red. It occurs
in ruptures anal fissures, hemorrhoids (piles), or ulcers and tumors of the colorectum.
6. Weight loss: it may be due
· Impaired food intake: as in eating disorders
· Malabsorption syndromes
· Increased catabolism a/w a malignant tumor.
7. Anaemia: it may be due to blood loss or due to impaired absorption of iron, folic acid or B12 (either due to a mucosal abnormality eg.
pernicious anaemia or to a defect in the transport proteins)
8. Diarrhoea: Causes: an impaired absorption (usually due to an infective cause as in cholera, shigellosis and are called infective diarrhoeas) or excessive secretion of fluid (osmotic diarrhoea- as in lactose intolerance)
9. Steatorrhoea: due to impaired absorption of fat either because of reduced lipase secretion or reduced absorption area or due to lymphatic obstruction.
Mouth
Ulcers: The oral mucosa is commonly affected by ulcers. These may be infectious (herpes virus, candida albicans) or non infectious (aphthous ulcers- due to an
immunological imbalance, or associated with Crohn’s disease- usually self limited).
Leukoplakia: premalignant lesion resulting from a chronic irritation- if untreated leads to squamous cell carcinoma.
Leukoplakia- hyperkeratosis
Aphthous ulcers
PHARYNX
Most infections of the pharynx are due to a viral infection like influenza, measles, rhinovirus, infectious
mononucleosis. Bacterial infections due to streptococcus
important because of their complications, like rheumatic fever and its complications, glomerulonephritis, and vascultis.
Tumors: Ebstein Barr virus is implicated in the development of Nasopharyngeal carcinoma.
Salivary glands Inflammations of the salivary glands is called sialedinitis.
It may be due to bacterial/ viral infections or autoimmune reaction.
Bacterial infections can act as a nidus for stone formation, resulting in duct obstruction.
Tumors: the most common tumor of the salivary gland is the mixed
tumor or the pleomorphic adenoma. The adenoid cystic carcinoma is a malignant tumor of the
salivary glands that involves the parotid gland, and commonly extends and infiltrates into the facial nerve leading to paralysis.
Esophagus Congenital conditions like
Atresia (failure to canalize/ absence of the lumen) Diverticula (formation of outpouchings in the wall) Tracheoesophageal fistula (fistula-abnormal connections between two hollow organs) may be
seen. Hiatus hernia is the presence of a part of the stomach above the diaphragmatic orifice. It may be
due to a congenital shortening of the esophagus, or in aged patients due to increased abdominal pressure coupled with a decreased diaphragmatic
muscle tone. Achalasia is a condition when the contractility of the lower esophagus is lost and failure of
relaxation of the sphincter. It may be due to destruction or degeneration of the myentric plexus as in neurotropic infection like Chaga’s
disease or due a congenital absence of the ganglion cells of the myentric plexus.
Esophageal atresia
A,B-Tracheoesophageal fistulas
C- Esophagela atresia with fistula
A B C
Oesophageal varices are dilated veins of the lower esophagus, which serve as shunts when portal venous flow through the liver is impaired. It is a cause for massive hematemesis. Other sites of varices are around the anus and the umbilicus.
Reflux esophagitis is a chronic inflammation in the esophagus occurring as a result of the regurgitation of the acidic gastric contents. It produces heartburn
Barrett’s esophagus is a metaplastic change in the mucosal lining of the lower esophagus, from stratified nonkeratinized epithelium to columnar epithelium, occurring as a result of longstanding reflux. Its significance lies in the fact that it is premalignant.
Tumors involving the oesophagus could be benign like the leiomyoma (smooth muscle tumor) or carcinoma (squamous cell carcinoma or the adenocarcinoma).
StomachCongenital pyloric stenosis is the hypertrophy of the circular
muscle coat of the pyloric sphincter leading to an outflow obstruction.
Acute gastritis: It is the acute inflammation of the stomach in response to an
irritant chemical like drugs or alcohol. The principal drugs implicated are the nonsteroidal anti-
inflammatory drugs (NSAIDs), notably aspirin. These agents result in exfoliation of the surface epithelial cells
and decrease the secretion of the mucus. Inhibit the prostaglandin synthesis.
Other causes include excessive alcohol ingestion, heavy smoking, cancer chemotherapy, severe stress as in burns/trauma/surgery (Curling’s ulcers), irradiation, ingestion of acids/ alkali, systemic infection and ischemia and shock.
Depending on the severity there may be lesions ranging from vasodilatation and edema to erosions and hemorrhage. Erosion is a partial loss of mucosa whereas an
ulcer is a full thickness loss. Erosions in acute gastritis are usually multiple and frequently bleed causing hemorrhage.
Chronic gastritis is frequently due to Helicobacter pylori infection, or may be autoimmune (associated with vitamin B12 deficiency resulting in megaloblastic anemia- pernicious anemia) or chemical injury due to NSAIDs, chronic bile reflux or alcohol, radiation, post surgery, obstruction, and chronic granulomatous conditions like Crohn’s disease.
Peptic ulceration Ulcers are a breach in the continuity of the mucosal epithelial lining of the
alimentary tract extending through the muscularis mucosa into the submucosa or deeper, arising as a result of the acid and pepsin attacks on the mucosa.
Normally these attacks are counteracted by the defense mechanism like the mucus- bicarbonate barrier, increased mucosal blood flow, increased regenerative capacity of the epithelium and prostaglandin secretion by the epithelium.
Ulcers result when the mucosal defenses are weakened or when the damaging forces are increased.
This occurs in:
1. Helicobacter pylori infection-
1. releases enzymes (digests the mucosal lining) and
2. lipopolysaccharides (attract the inflammatory cells which release digestive enzymes) and
3. a platelet activating factor that promotes the thrombotic occlusion of the surface capillaries (promotes ischemic damage)
2. Chronic use of NSAIDs- these suppress the prostaglandin secretion
3. Increased gastric acidity as in gastrinomas (increased gastrin secretion)- Zollinger Ellison syndrome.
4. Chronic smoking, alcohol ingestion, corticosteroid administration are other causes.
Major sites include first part of the duodenum, junction of the
antrum and the body of the stomach, distal oesophagus, at the
gastro enterostomy stoma (post partial gastrectomy patients) and
in Meckles diverticula (sac like out pouching from the intestinal
wall)
Clinically the patient presents with a burning pain, which is
worse at night and 1-3 hours after meals, nausea, vomiting,
bloating, belching, and weight loss.
Complications of the ulcers include hemorrhage, anemia,
extension and perforation of the ulcers, and obstruction due to
healing by fibrosis.
IntestinesCongenital abnormalities include atresia, stenosis, diverticula and
Hirschsprung’s disease (absence of ganglion cells in the large intestine (rectum and sigmoid colon).
Malabsorption: The sub optimal absorption of nutrients (carbohydrates, proteins, fats, vitamins, electrolytes and minerals) and water. It is classified as due to
1. Defective digestion: due to deficiency of enzymes2. Mucosal cell abnormalities: results in defective terminal
digestion and/or defective transport of the nutrients3. Reduced small intestinal surface area: Celiac sprue or
Iatrogenic: post surgical resection 4. Lymphatic obstruction: due to lymphoma or tuberculosis:
resulting in deficient fat absorbtion5. Infections: tropical sprue, parasites, and Whipple’s disease.
The clinical consequences of malabsorption syndromes
1. Alimentary tract: diarrhea, pain, weight loss, passage of bulky,
greasy stools
2. Hematopoietic system: causes anemia, bleeding
3. Musculoskeletal system: osteopenia and tetany (hypocalcemia)
4. Endocrines: amenorrhea, impotence, infertility and
hyperparathyroidism
5. Skin: purpura, petechia, edema, dermatitis
6. Nervous system: peripheral neuropathy
Idiopathic inflammatory bowel disease
It includes Crohn’s disease and ulcerative colitis
Crohn’s disease is a granulomatous disease affecting any portion of the gut
but most often the small intestine and colon.
Ulcerative colitis is a non-granulomatous inflammatory disorder involving
the colon.
Both the diseases are unexplained (idiopathic) but some etiological
factors are implicated like:
Genetic (familial clustering is noted), infectious agent may be the cause (as
there is inflammation), or abnormal host immunoreactivity.
Feature Crohn’s disease Ulcerative colitis
Site Throughout the GIT The colon starting from the rectum
Distribution Skip lesion Continuous lesion
Stricture & Fibrosis Occurs early in the disease due to marked fibrosis
Rare/ occurs late as fibrosis is to a lesser degree
Wall Thickened Thin & Dilated
Ulcers Deep and linear Superficial
Fistulas Present Absent
Pseudopolyps Absent Present
Granulomas Present Absent
Extra intestinal manifestations
Arthritis, Ankylosing spondylitis Uveitis, Cholangitis and Erythema nodosum
Occur but to a lesser extent
Malignant potential & Prognosis
Definite riskPoor prognosis
Present but rarerGood prognosis
Fat & vitamin malabsorption
Present Absent