Primary Care: Abdominal Pain & Gastroenteritis
Leslie Hershberger, MD
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
Abdominal pain
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 Biliary and pelvic symptoms Evaluate vasculature, inflammation, and solid organs
Ultrasound
CT abdomen and pelvic
Differential Diagnoses
Acute
Chronic
Appendicitis Cholecystitis Pancreatitis Diverticulitis Perforation Obstruction Acute ischemia Ruptured aortic aneurysm Ectopic pregnancy PID Nephrolithiasis
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
The End!