Gastrointestinal Tract

Anatomy

mouth•teeth•tongue•salivary glands

esophagus

pharynx

stomach

small intestine

colon

liver

gallbladder

pancreas

Functions

1. Ingestion: eating

2. Secretion: release of water, enzymes & buffers3. Mixing & propulsion: movement along GI tract4. Digestion: mechanical and chemical breakdown of

foods5. Absorption: getting it into the body6. Defecation: dumping waste products = defecation

DigestionProteins

Carbohydrates

Fats

Fig. 16.9Fig. 16.9

Fig. 16.2Fig. 16.2

Diagnostic techniquesCBC

Upper GI series

Barium enema

UTZ

CT scan

Disorders of the Digestive System

Reflux esophagitis

gastritis

peptic ulcers

irritable bowel syndrome

neoplasms

Reflux EsophagitisLES

Heartburn

Barret’s Esophagus

Antacids

H2-receptor blockers

GastritisInflammation of the lining of the stomach

The stomach lining may be "eaten away," leading to sores (peptic ulcers) in the stomach or first part of the small intestine.

Left untreated, these ulcers may bleed

Gastritis can occur suddenly (acute gastritis) or gradually (chronic gastritis).

Signs and Symptoms:

most common - stomach upset and pain

Other symptoms of gastritis: * Indigestion (also called dyspepsia) * Heartburn * Abdominal pain * Hiccups * Loss of appetite * Nausea * Vomiting, possibly of blood (called hematemesis) or material that looks like coffee-grounds * Dark stools

Causes

• infection, • irritation, • autoimmune disorders (disorders caused by the body's immune response against its own tissues), or • backflow of bile into the stomach (bile reflux)

Infections can be any of the following types:

* Bacterial (usually Helicobacter pylori ) * Viral (including herpes simplex virus) * Parasitic * Fungal

Irritation can be caused by a number of things, such as the following:

* Long-term medication use (for example, aspirin, ibuprofen or other anti-inflammatory drugs [called NSAIDS]) * Alcohol use * Cigarette smoking * Chronic vomiting * Coffee and acidic beverages * Excess gastric acid secretion (such as from stress) * Eating or drinking caustic or corrosive substances (such as poisons) * Trauma (for example, radiation treatments or having swallowed a foreign object)

Helicobactor pylori- a common bacterial cause of gastritis and ulcersTreated with a combination of drugs.

antibiotics, a bismuth compound, and a proton pump inhibitor. (Proton pump inhibitors reduce stomach acid secretion.)

taken for at least 14 days.

In addition to the medications used for Helicobacter pylori infection, other medications that may be used to relieve symptoms of gastritis include those that reduce stomach acid secretion:

* Antacids such as calcium carbonate and magnesium hydroxide with aluminum salts * H2 blockers such as ranitidine, cimetidine, nizatidine, and famotidine * Proton pump inhibitors such as omeprazole and lansoprazole

Drugs that reduce stomach acid secretion help protect against or treat ulcers. Other drugs used for ulcers include:

* Misoprostol – protects against the major intestinal toxicity of NSAIDS, and can reduce the formation of ulcers * Sucralfate – helps to heal ulcers in the stomach

Peptic ulcersstomach and proximal duodenum

smoking, NSAIDS, steroid, alcohol, family history

duodenal - benign; gastric - malignant

H. pylori

endoscopy and biopsy

antacids with antibiotic

Diarrhea increased volume and liquidity of stool

secretoryosmotic

fluid replacement

Constipation less than 3 bowel movements per week

low fiber diet or a disease process

Appendicitisabdominal pain

RLQ

surgery

Acute Pancreatitisacute inflammation of the pancreas with

edema, autodigestion, necrosis and hge.

alcohol ingestion & biliary tract dse.

nausea & vomiting usually not present

IV fluid replacement and pain relievers

NGT suction

Acute cholecystitis inflammation of the gall bladder

obstruction of the cystic duct

crampy epigastric or RUQ postprandial pain

fever, nausea and vomiting

jaundice

surgery

Cholelithiasisgallstone in the common bile duct

fever, jaundice, RUQ pain (Charcot’s triad)

antibiotics

surgical - Cholecystectomy

CholelithiasisCholesterol stones

radiolucent with 10-20% opaque (calcifications)associated with Obesity

Pigment stones radiopaquealcoholic cirrhosis and biliary infection

Mixed stones radiolucentmost common type

Viral HepatitisHAV, HBV, HCV

jaundice, hepatomegaly, tender

HAV - fecal-oral

HBV - parenteral

HCV - parenteral

vitamin K

no specific therapy

Viral HepatitisHBsAg - infected

HBsAb - treated/immune/vaccinated

HBeAg - infectious

HBeAb - non-infectious

HBcAg – chronic/carrier

Alcoholic Liver Dse. leads to Liver

cirrhosis

Cirrhosis (Portal Hypertension)

diffuse fibrosis of liver, destroys normal architecture

Nodular regenerationMicronodular

<3mmuniform sizedue to metabolic insult (alcohol)

Cirrhosis (Portal Hypertension)

Macronodular>3mmvaried sizedue to significant liver injury leading to hepatic

necrosis (postinfectious or drug induced hepatitis) Increased risk of hepatocellular carcinoma

Cirrhosis (Portal Hypertension)esophageal varices

hematemesisMelena

peptic ulcerSplenomegalyCaput medusae/Spider angiomaAscitesHemorrhoids

GI BleedHematemesis

Melena

Hematochezia

Peutz-Jeghers Syndrome (PJS)an autosomal dominant inherited disorder

characterized by intestinal hamartomatous polyps in association with mucocutaneous melanocytic macules.

15-fold increased risk of developing intestinal cancerincludes gastrointestinal and

extraintestinal sites.

Inflammatory Bowel Diseases

Ulcerative Colitis

idiopathic chronic inflammatory disorder limited to the colon

lifelong illness that has a profound emotional and social impact on patients who are affected.

rectum (>95% of cases), extends proximally from the anal verge in an uninterrupted pattern to involve part or all of the colon.

Ulcerative Colitis

* Frequent episodes of rectal bleeding occur, with or without mucus. The characteristic feature is blood in each bowel movement.

* Urgency and tenesmus

* Abdominal cramps

* Weight loss in severe cases

Crohn's Diseaseform of inflammatory bowel disease (IBD)

usually affects the ILEUM, but may occur anywhere from the mouth to the end of the rectum (anus).

Causes: autoimmune disorder

ongoing (chronic) inflammation of the GIT --> healthy patches of tissue between diseased areas --> causes the intestinal wall to become thick.

A person's genes and environmental factors seem to play a role in the development of Crohn's disease. The body may be overreacting to normal bacteria in the intestines.

Crohn's Disease

5 different types of Crohn's disease:

* Ileocolitis is the most common form. It affects the lowest part of the small intestine (ileum) and the large intestine (colon).

* Ileitis affects the ileum.

* Gastroduodenal Crohn's disease causes inflammation in the stomach and the duodenum.

* Jejunoileitis causes spotty patches of inflammation in the jejunum.

* Crohn's (granulomatous) colitis only affects the large intestine.

INCREASED RISK OF DEVELOPING CANCER

The main symptoms of Crohn's disease are:

* Crampy abdominal (belly area) pain

* Fever

* Fatigue

* Loss of appetite

* Pain with passing stool (tenesmus)

* Persistent, watery diarrhea

* Unintentional weight loss

Other symptoms may include:

* Constipation

* Eye inflammation

* Fistulas (usually around the rectal area, may cause draining of pus, mucus, or stools)

* Joint pain

* Liver inflammation

* Mouth ulcers

* Rectal bleeding and bloody stools

* Skin rash

* Swollen gums

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