Primary Care:Abdominal Pain &

Gastroenteritis

PROF/ GOUDA ELLABBAN

Objectives

I. ABDOMINAL PAIN Obtain a targeted history in a pt with abd

pain Perform a physical exam to determine cause

of pain Interpret lab tests to determine etiology of

pain Describe the differential dx of abd pain

Types of Abdominal Pain

Visceral Somatic Referred

Visceral Pain

Originates from internal organs and viceral peritoneum

Results from stretching, inflammation, or ischemia

Dull, crampy, burning, gnawing Poorly localized

Somatic Pain

Originates from abdominal wall or parietal peritoneum

Sharper, more localized

Referred pain

Pain felt in areas remote to the disease organ

History Onset (acute vs. chronic) Duration of pain Location Radiation Quality and severity Associated symptoms Alleviating or aggravating factors Past medical/surgical history

Physical Exam

Vital signs Constitutional findings Abdomen- inspection, auscultation,

percussion, palpation Pelvic exam Rectal exam Cardiac/ respiratory exam

Physical Exam

Start away from area of pain Look for areas of localized tenderness Rebound/guarding Masses or enlarged organs

Lab Evaluation

CBC with diff LFT, amylase, lipase UA HCG on reproductive age women electrolytes

Radiologic Evaluation

Plain films Upright and supine abdomen and CXR

Ultrasound Biliary and pelvic symptoms

CT abdomen and pelvic Evaluate vasculature, inflammation, and solid

organs

Differential Diagnoses Acute

Appendicitis Cholecystitis Pancreatitis Diverticulitis Perforation Obstruction Acute ischemia Ruptured aortic

aneurysm Ectopic pregnancy PID Nephrolithiasis

Chronic Peptic ulcer Esophagitis IBD Chronic pancreatitis Chronic ischemia Diabetes Irritable bowel

syndrome Abdominal wall pain

Neurogenic musculoskeletal

Differential

Acute Cholecystitis Cystic duct obstructed RUQ or epigastric pain radiating to R

scapula n/v, fever Murphy’s sign or tender enlarged

gallbladder LFTs, amylase

Differential

Acute appendicitis Anorexia, fever, n/v vague periumbilical pain that

progresses to RLQ (McBurney’s point) Rovsing’s, psoas, obturator signs Elevated WBC CT may be useful in dx

Differential

Small Bowel Obstruction Due to adhesions, hernia Crampy, periumbilical pain, n/v, high

pitched bowel sounds Xray- dilated loops of bowel with AF

levels Partial vs complete obstruction

Differential

Perforated duodenal ulcer usually in ant duodenal bulb Acute abdomen with peritonitis CXR with free intraperitoneal air under

diaphragm

Differential

GYN Ectopic pregnancy Ovarian torsion PID/TOA

Chronic Abdominal Pain

Abd pain lasting > 6 months Differentiate organic pain from a

pathologic process from functional pain

Functional pain more common

Irritable Bowel Syndrome

Affects 15% of Americans Abd distention, flatulence, disordered

bowel function More common in women Treat with anticholinergic meds and

stool softeners

Benign Chronic Abd Pain Syndrome

Pain present for months to years Negative workup Women > men Obtain social history (sexual/physical

abuse) May need psych evaluation or pain

management specialist

Summary

Obtain detailed history Thorough exam Consider pt circumstances (age,

med/surgical history) Evaluate for progression Consult if needed

Objectives

II. Gastroenteritis Describe the usual cause of

gastroenteritis Describe the signs and symptoms Perform focused physical exam Interpret diagnostic tests to determine

etiology of gastroenteritis Treat selected pts with gastroenteritis

Gastroenteritis

Inflammation of GI tract Due to infectious virus, bacteria, or

protozoa Acute onset Usually < 10 days Self limiting

Etiology

Microbes directly invade gut mucosa Microbes secrete toxins

Entertoxin Cytotoxin neurotoxin

Etiology Bacteria

Campylobacter jejuni (most common in US)

Shigella Salmonella E. Coli Vibrio cholera Yersinia C. dificile Vibrio Parahaemolyticus

Etiolgy

Viral Rotavirus Norwalk virus Adenovirus Calicivirus Coronavirus astrovirus

Etiology

Protozoa Giardia lamblia Entamoeba histolytica Cryptosporidium parvum Isospora belli

Etiology

Heavy metal (arsenic, lead, Hg, cadmium)

Broad spectrum antibiotics Antacids Laxatives Cardiac meds

Symptoms

Fever n/v Diarrhea Abd cramping Malaise and muscular aches may

occur

History

Ingestion of potentially contaminated food or untreated water

Recent travel Sick contacts Recent Abx use Outbreaks Bloody diarrhea

Physical Exam

Vital signs Constitutional findings Abdomen- inspection, auscultation,

percussion, palpation Pelvic exam Rectal exam Cardiac/ respiratory exam

Diagnosis

Stool exam for fecal WBCs, ova , parasites

Stool culture Endoscopy if noninfectious etiology

suspected (inflammatory bowel disease)

Treatment

Rehydration – oral vs. IV Antiemetics Antidiarrheals

Decrease intestinal motility Diphenoxylate, loperamide, codeine

+/- antibiotics Shigella, Yersinia, campylobacter,

cholera, c. dificile, giardia

Antibiotic associated diarrhea

Develops in 1-15% of pts receiving broad spectrum abx

C. Dificile proliferates in colonic mucosa when normal flora is disturbed

May cause pseudomembranous colitis Stop responsible abx Stool assay for C. dif toxins Rx:

Moderately ill- flagyl 500 mg q8hr x 7 days Extremely ill- oral vancomycin