THE MAIN METHODS OF FUNCTIONAL DIAGNOSTICS OF DISEASES OF GASTROENTEROLOGY

Small Intestine and Colon Small intestine –Begins at pyloric sphincter –Duodenum –Jejunum –Ileum –Mesenteric small intestine Colon –Cecum Appendix –Ascending colon –Transverse colon –Descending colon –Rectum, anus

Anatomy/Blood Supply of Colon/Rectum

Pathophysiology Pseudomembranous enterocolitis –Inflammation of the small or large bowel, usually as a result of an infective disease. The most common causative organisms include rotaviruses and other enteric viruses and other enteric viruses, including Salmonella, E. Coli, Shigella, Campylorbacter, and Yersinia species. A potentially severe presentation, Pseudomembranous enterocolitis, may be induced by prolonged use of antibiotics allowing overgrowth of Clostridium difficile. Polyps

Pathophysiology Mechanical Lesions –Large bowel obstruction Band/adhesion Malignancy –Volvulus –Intussussception –Fecal Impaction Trauma: Blunt and Penetrating Inflammatory: Diverticulosis/Diverticulitis, Ulcerative Colitis, Crohn’s disease Vascular: Ischemic colitis, vascular occlusion/infarction arterio-venous malformation

Diagnostics: Exams Barium Enema IVP if renal involvement is suspected CT Scan/MRI Sigmoidoscopy/Colonoscopy Hemoccult/Guaiac

Diagnostics: Medical History Blood work –CBC –Electrolytes –PT/PTT Urinalysis Chest-x ray ECG

Computed Tomography (CT) or (CAT) Painless, noninvasive x-ray procedure that has the unique capabilities of distinguishing minor differences in the density of tissues. It produce a three – dimensional image of the organ or structure.

Magnetic Resonance Imaging (MRI) Is a noninvasive diagnostic scanning technique in which the client is placed in a magnatic field. MRI provides a better contrast between normal and abnormal tissue than the CT scan. For visualization of the brain, spine, limbs, and joints, heart, blood vessels, abdomen and pelvis. The procedure lasts between 60 and 90 minutes.

Visualization Procedures It includes indirect visualization (noninvasive) and direct visualization (invasive) techniques for visualizing body organ and system function. Clients with Gastro intestinal Alteration: Direct visualization techniques include: Anoscopy: viewing of the anal canal Proctoscopy: viewing of the rectum Proctosigmoidoscopy: viewing the rectum and sigmoid colon Colonoscopy: viewing of the large intestine.

Indirect visualization of the gastrointestinal tract is achieved by: X-rays of gastrointestinal tract can detect structure, obstructions, tumors, ulcers, inflammatory diseases or other structural changes such as hiatal hernias. Visualization of the tract is enhanced by the use of a barium. For examination of the upper gastrointestinal tract or small bowel, the client drinks the barium sulfate (barium swallow). For examination of the lower gastrointestinal tract, the client is given an enema containing the barium (Barium enema).

Barium Swallow

Upper endoscopy

Liver function tests Noninvasive method of screening for the presence of liver dysfunction Pattern of lab test abnormality allows recognition of general type of disorder To assess the severity and occasionally allow prediction of outcome To follow the course of the disease, evaluate response to treatment, and adjust treatment when necessary

Limitations Lack of sensitivity (may be normal in cirrhosis or HCC) Lack of specificity (aminotransferase levels may be elevated in musculoskeletal or cardiac disease) Results suggest general category of liver disease, not a specific diagnosis Essential to use LFT as a battery of tests and repeat them over time Probability of liver disease is high when more than one test is abnormal or the findings are persistently abnormal on serial testing

General categories of tests Tests of the capacity of the liver to transport organic anions and metabolize drugs Eg. S bilirubin, s bile acids, BSP etc Measures ability of the liver to clear endogenous or exogenous substances from the circulation  Tests to detect injury to hepatocytes All the enzyme tests Most commonly done and most useful are aminotransferases and alkaline phosphatase

Tests of the biosynthetic capacity of the liver Tests to detect fibrosis in the liver Tests for chronic inflammation or altered immunoregulation Eg. S albumin, prothrombin time Eg. Type 4 collagen, Fibrotest etc Immunoglobulins and specific antibodies Schiff’s diseases of the liver, 2007

Common serum liver chemistry tests

Normal values