Gastrointestinal Diseases Flashcards
Dyspepsia meaning
broad spectrum of epigastric symptoms: heartburn, indigestion, bloating, epigastric pain/discomfort
Dyspepsia/heartburn etiology
most cases (up to 90%) due to peptic ulcer dz, GERD, gastritis, or nonulcer dyspepsia (functional dyspepsia)
Dyspepsia often confused with…
angina!
Nonulcer dyspepsia
- dx of exclusion after appropriate tests (including endoscopy) do not reveal specific cause
- dyspepsia symptoms must be present for at least 4 wks to make dx of nonulcer dyspepsia
Test of choice for evaluation of dyspepsia
endoscopy;
but should not be used routinely; focus on:
- pts with alarming symptoms (wt loss, anemia, dysphagia, obstructive symptoms)
- pts >45-50 yrs w new onset dyspepsia
- recurrent vomiting, evidence of upper GI bleed
- pts not responding to empiric therapy
- pts with signs of complications of PUD
- pts with recurrent sx
- pts with evidence of systemic illness
if GERD + dysphagia
suggests devt of peptic stricture;
alternatives: motility disorder or cancer
GERD mxn + 1 important contributing factor
multifactorial
most often 2/2 decreased LES tone
hiatal hernias are common findings in patients with GERD
Diagnostic tests for GERD
usually not nec for typical uncomplicated GERD; therapy can be initiated
Tests indicated for: atypical, complicated, or persistent cases (despite treatment)
Endsoscopy (with biopsy) if: worrisome symptoms (anemia, weight loss, dysphagia)
24 hr pH monitoring in lower esophagus = most sensitive and specific test for GERD = gold standard! but usually not necessary
Clinical features GERD
heartburn, dyspepsia: retrosternal pain, may mimic cardiac chest pain
GERD = chronic disorder
GERD=chronic disorder
regular followup to identify complications (Barrett’s esophagus, stricture, esophagitis)
Peptic stricture (fibrotic rings narrow lumen of esophagus) may mimic…
esophageal cancer (presents with dysphagia)
EGD can confirm
Recurrent pneumonia due to recurrent pulmonary aspiration
cytologic aspirate finding on bronchoscopy that can dx aspiration of gastric contents = lipid-laden macrophages (from phagocytosis of fat)
Screening for Barretts
pts with symptomatic GERD for >= 5 yrs and can undergo surgery if cancer is found
–> if documented Barrett’s esophagus without dysplastic changes, periodic surveillance (every 3 or so yrs)
Treatment erosive esophagitis
Proton pump inhibitor
Diarrhea Clinical Pearls
- acute diarrhea: usually due to infection (virus, bacteria, parasite) or medications
- if nausea and vomiting present: suspect viral gastroenteritis or food poisoning
- if food poisoning is cause: diarrhea appears within hours of meal
- occult blood in stool may be present in all types of acute infectious diarrhea, but its much less common to have gross blood
- fever + blood together: typical of infection with shigella, campylobacter, salmonella (may also be without blood), enterohemorrhagic e.coli (EHEC)
- no fever + no blood: typical of infection with viruses (rotavirus, Norwalk virus), enterotoxic E.coli (ETEC), and food poisoning (s.aureus, c.perfringens)
Acute vs chronic diarrhea
acute: 4 wks
Medications causing diarrhea
==> antibiotics most common cause: abx associated diarrhea caused by C.difficile toxin in 25% of cases
others: laxatives, prokinetic agents (cisapride-in book but goodman & gilman says no longer used), antacids (magnesium “makes you go”?), chemotherapeutic agents, digitalis, colchicine (gout), alcohol
Chronic diarrhea
IBS most common cause, but dx of exclusion
Acute diarrhea
Infection (viruses most common > bacteria > parasites), and medications
Clinical pearl: important parts of history in patient with diarrhea
- is stool bloody or melanotic?
- are there any other symptoms (fever, abdominal pain, vomiting)
- is there anyone in the family or group with a similar illness
- has there been any recent travel outside the US, or any hiking trips? (parasitic infections)
- are symptoms linked to ingestion of certain foods (e.g., milk)
- are there any medical problems (e.g., AIDS, hyperthyroidism)?
- have there been any recent changes in medications (e.g., antibiotics within past few weeks)
Diagnosis of diarrhea: patient evaluation
assess volume status (dehydration is a concern), perform abdominal exam, check stool for occult blood in pts with diarrhea.
in mild to moderate case of acute diarrhea, further workup unnecessary.
Fecal leukocytes present in:
campylobacter, salmonella, shigella, enteroinvasive e.coli, c.difficile
Fecal leukocytes absent in:
staphylococcal or clostridial food poisoning; viral gastroenteritis
Laboratory tests to consider in evaluating diarrhea
stool wbcs, stool for ova and parasite (3 samples), stool culture, stool for c.difficile culture, stool for c.difficile toxin assay (if pt treated with abx recently, treat empirically before results return if suspicion high), stool for giardia antigen
Pathogens causing diarrhea with fecal leukocytes and often blood
salmonella, campylobacter, shigella, enteroinvasive e.coli
Most common electrolyte/acid-base abnormalities seen with severe diarrhea
- metabolic acidosis
2. hypokalemia
Approach to pt with acute diarrhea: no complications
Acute diarrhea –> history, physical exam –> no complications –> symptomatic treatment: rehydration, consider loperamide (increases small instestinal and mouth-to-cecum transit times, increases sphincter tone, anti-secretory activity against cholera toxin and some forms of E.coli toxin)
Approach to patient with acute diarrhea: complications and positive stool for WBC
acute diarrhea –> history, PE –> complications: bloody stool, systemic symptoms/fever, dehydration, abdominal pain/nausea/vomiting –> positive –> stool culture, consider c.difficile toxin : if positive, treat; if negative, ask if diarrhea persists longer than expected: if so flexible sigmoidoscopy with biopsy
Approach to patient with acute diarrhea: complications, negative stool for WBC
acute diarrhea –> history, PE –> complications (bloody stool, systemic symptoms/fever, dehydration, abdominal pain/nausea/vomiting –> microscopic examination of stool for WBC negative –> symptomatic treatment; if diarrhea persists for longer than expected do flexible sigmoidoscopy with biopsy
Diarrhea usually self-limited but treat in event of…
- dehydration (esp in elderly)
- pts initially unable to tolerate or hold down PO fluids
- bloody diarrhea (with profuse or brisk bleeding)
- high fever, toxic appearance
- -> identifying specific agent not critical in deciding treatment (treat based on med hx and clinical condition)
ABx and diarrhea
use of abx in infectious diarrhea can decrease duration by 24 hrs regardless of etiologic agent; consider 5day course of ciprofloxacin in pts with moderate to severe dz
abx def recommended if:
- pt has high fever, bloody stools, or severe diarrhea (quinolones appropriate)
- stool culture grows one of pathogenic organisms
- pt has travelers diarrhea
- c.diff infection (metronidazole)q
Loperamide (immodium)
only give if diarrhea mild to moderate;
not recommended if pt has fever or blood in stool
Constipation (causes)
- diet (lack of fiber)
- medications: anticholinergic drugs (antipsychotics), antidepressants, narcotic analgesics, iron, calcium-channel blockers, aluminum or calcium containing antacids, laxative abuse and dependence (?)
- IBS
- anorectal problems (hemorrhoids, fissures)
- obstruction: colorectal cancer (always keep this in mind!), anal stricture, hemorrhoids, anal fissure
- ileus, pseudo-obstruction
- anorectal problems: hemorrhoids, fissures
- endocrine/metabolic causes: hypothyroidism, hypercalcemia, hypokalemia, uremia, dehydration
- neuromuscular disorders: Parkinson’s disease, multiple sclerosis, CNS lesions, scleroderma, diabetes mellitus (autonomic neuropathy)
- congenital disorders: Hirschsprung’s disease
Laboratory tests that may be needed to dx constipation
TSH, serum calcium levels, CBC (if colon cancer suspected), and electrolytes (if obstruction suspected)
- always try to rule out obstruction* (if h & p suggestive order abd films, flexible sigmoidoscopy if obstructing colorectal mass suspected)
- rectal exam: can help identify fissures, hemorroids, fecal impaction, or masses
Complications of chronic constipation
hemorrhoids, anal fissures, rectal prolapse, fecal impaction
Common pathogens responsible for acute infectious diarrhea (distinctive features only)
1) acute viral gastroenteritis (rotavirus, Norwalk virus): myalgias, malaise, nausea/vom; 2-3 days of symptoms up to 1 wk; fecal-oral transmission; most common cause of acute diarrhea in US; look for similar illness in family members
2) salmonella: abd pain, n/v, resolves within 1 week, food (eggs/domestic fowls), symptoms within 1-2 days ingesting food; no treatment except immunocompromised ppl or enteric fever (salmonella typhi); cipro
3) shigella: tenesmus, less common to have n/v, resolves within 1 wk, fecal oral > food, treat with tmp/smx
4) staphylococcus food poisoning: abd/n/v; within 24 hours; food; ill within 1-6 hours; can be severe and require hospitalization
5) campylobacter jejuni: headache, fatigue –> diarrhea + abd, food, most common cause of acute bacterial diarrhea, can be severe (blood in stool in 50% of cases); treat with erythromycin; relapse may occur
6) clostridium perfringens: crampy abdominal pain is prominent; vom and fever rare; within 24 hours, food,
7) enterotoxic e.coli: watery diarrhea, n/abd pain; few days; food ; self limiting common in developing countries
8) e.coli (O157:H7): blood diarrhea, pt can appear sick, food (undercooked meat, raw milk), hemorrhagic colitis usually self limited); has been associated with hemolytic uremic syndrome + thrombotic thrombocytopenic purpura
9) giardiasis: watery, foul smelling diarrhea; abd bloating; 5-7 days sometimes longer; fecal oral, food, contaminated water; treat with metronidazole
10) vibrio cholera: voluminous diarrhea (“rice water” stools), abd/vom, low grade fever, rare in US but common in developing countries
Irritable Bowel Syndrome ddx
Ddx IBS:
colon cancer, IBD, drugs, mesenteric ischemia, celiac disease, ischemic colitis, giardiasis, pseudo obstruction, depression, somatization, intermittent sigmoid volvulus, megacolon, bacterial overgrowth syndrome, endometriosis
IBS pearls
idiopathic, assoc with intrinsic bowel motility dysfunction (abn resting activity of gi tract_
10-15%
asso findings: depression, anxiety , somatization
symptoms exacerbated by stress and irritants in intestinal lumen
symptoms must be persistant for at least 3 months to dx
all lab test results are normal, no mucosal lesions found on sigmoidoscopy
INitial tests that may help exclude other causes (bc IBS is dx of exclusion)
CBC, renal panel, fecal occult blood test, stool examination for ova and parasites, erythryocyte sedimentation rate, possibly flexible sigmoidoscopy
order only if suspicion of other causes for sx
Treatment of IBS
diarrhea: diphenoxylate (includes atropine; binds gut wall opioids receptors, inhibits peristalsis; subtherapeutic atropine = anticholinergic present to discourage overdose) or loperamide (bind gut wall opioid receptors, inhibit peristalsis, increase anal sphincter tone)
constipation:
colace: facilitates mixutre of stool fat and water; class c risk in preg (risk unknown)
psyllium: increases stool bulk
cisapride: enhance myenteric plexus acetylcholine release, promoting gastric motility
The following must be excluded in diagnosing IBS
- obstruction (plain abdominal film)
- inflammatory bowel disease
- lactose or sorbitol intolerance
- malignancy (in older pts or those with fam hx)-colonoscopy, occult blood in stool
Gastroenteritis quick hits
typically caused by an enterovirus, and seen in groups among family members, colleagues, etc
diarrhea often present but may appear later
Nausea and vomiting causes
- pregnancy
- metabolic: diabetic ketoacidosis, addisonian crisis, uremia, electrolyte disturbance (hypercalcemia, hypokalemia), hyperthyroidism
- GI: gastroenteritis (viral most common; food poisoning eg salmonella, shigella, and cholera); PUD; GERD, gastric retention (gastroparesis in diabetic patients, gastric outlet obstruction; intestinal obstruction (small bowel obstruction or pseudo obstruction), ileus ; peritonitis
- acute visceral conditions (pancreatitis, appendicitis, pyelonephritis, cholecystitis, cholangitis)
- neurologic: increased intracranial pressure, vestibular disturbance (vertigo), migraine headache
- acute MI
- drugs (medications, toxins): chemotherapy meds (esp cisplatin), digitalis toxicity, nsaids and aspirin, narcotics, antibiotics (erythromycin), xs alcohol intake
- miscellaneous: motion sickness, systemic illness, radiation therapy, post operatively
- psychiatric: eating disorder (bulimia, anorexia nervosa), anxiety
Approach to nausea and vomiting (hx) in history
questions to ask: recent food intake (unusual timing of onset of vom relative to food, anyone else eat food, symtpoms related to meals), meds and recent changes /additions, hx of abd (obstruction) or recent sx, fam members wtih simlar illness
define the vomitus
bilious: obstruction distal to ampulla of vater
feculent: distal intestinal obstruction, bact overgrowth, gastrocolic fistula
vomiting of undigested food: esophageal prob more likely (achalasia, stricture, diverticulum)
projectile vom: increasaed intracranial pressure or pyloric stenosis
coffee ground material or blood: GI bleed
accompanying symptoms
diarrhea and fever: infectious such as gastroenteritis
abd pain: obstruction, acute inflamm conditions (peritonitis, cholecystitis)
headache, visual disturbances, other neuro findings: increased ICP or intraocular pressure
Possible complications severe or prolonged vomiting
- fluid/electrolytes (dehydration, hypokalemia, metabolic alkalosis)
- dental caries
- aspiration pneumonitis
- GI: mallory weiss tears, boerhaaves syndrome, mallory weiss syndrome
Treatment vomiting
most causes self limiting if vom severe may –> dehydration req hospitalization
assess hydration status fluid replacement is 1st step in mgmt (use 1/2 normal saline with K+ replacement)
Most common electrolyte abnormality after severe vom:
hypokalemia with metabolic alkalosis
symptomatic relief of vom:
prochlorperazine: selective antagonizing of dopamine d2 receptors
promethazine: non selectively antagonizes centrla and peripheral histamine H1 receptors; possesses anticholinergic properties –> anti-emetic and sedative effects
Risk factors for hemorrhoids
1.constipation/straining; 2. pregnancy; 3. portal hypertension; 4. obesity; 5. prolonged sitting (esp truck drivers and pilots) ; 6. anal intercourse
Clinical features hemorrhoids
if bleeding (bright red blood per rectum): look for iron deficiency anemia
if occult bleeding: investigate more serious causes ; occult bleeding should never be attributed to hemorrhoids until other conditions ruled out
bleeding usually painless
