DSA 6: Diarrhea Flashcards
what are causes of constipation
MC: inadequate fiber/fluid intake
hypothyroid, hyperparathyroidism, paraplegia
opiods, anticholinergics, Ca2+ & Fe supplements
colonic mass w/ obstruction- adenoCA
colonic stricture: radiation, ischemia, diverticulosis
IBS
what is dual-energy x-ray densitometry recommended for
recommended for all pts w/ celiac to screen for osteoporosis
what is the etiology, Hz & PE of C. diff
hospitalized, ill, received ABx - Sxs begin during/right after ABsx therapy
mild-mod greenish, foul smelling watery diarrhea 5-15x/day
low abd pain, cramping, fever
PE: LLQ - normal/mild tenderness; severe/fulminant dz - hemodynamic instability, profuse diarrhea (30x/day)
How do you Dx Celiac dz
Abn serologic findings, small bowel Bx
Serology: IgA tTG antibody (recommended)
IgA anti-endomysial Ab
Anti-gliadin Ab (not tested any more)
Levels of all Ab undetectable after 3–12 months of dietary gluten withdrawal
IF pt = IgA deficiency –> IgG Ab to deamidated gliadin peptides (anti-DGP) & IgG tTG Ab
Endoscopy w/ Bx: Proximal and distal duodenum
atrophy or scalloping of the duodenal folds may be observed
Histology = intraepithelial lymphocytosis alone –> extensive infiltration of lymphocyte & plasma cell into LP –> hypertrophy of intestinal crypts and blunting or complete loss of intestinal villi
An adequate normal Bx excludes the Dx
what should be considered when pt complains about diarrhea
pseudo-diarrhea: freq passage of small vol stools; associated w/ rectal urgency, tenesmus, or feeling of incomplete evacuation, accompanies IBS/proctitis
fecal incontinence: involuntary discharge of rectal contents; caused by neuromuscular disorders or structural anorectal prob; diarrhea & urgency (esp if severe-may cause incontinence)
overflow diarrhea: severe consipation but only liquid gets by (elderly/nursing home pts); detect fecal imaction by rectam exam
what are characteristics of bile salt malabsorption
- bile salts resorbed in terminal ileum ; resection/dz of this area (eg, crohns)–> insufficient intraluminal bile salts
- destruction/loss of bile salts caused by bacterial overgrowth, massive acid hypersecretion, or meds that bind bile salts (eg, cholestyramine)
- mild steatorrhea (due to malabsorption of FA & monoglycerides) minimal wt. loss
- impaired abs of fat soluble vits (ADEK) –> b_leeding tendencies, osteoporosis, & hypoCa2+_
- watery secretory diarrhea
What are clues, Sx, Hx and MCC of osmotic diarrhea
Clues: stool vol decrease w/ fasting; increased osmotic gap (>50; 75)
Sx: abd distention, bloating, flatulence (increased gas production)
ask about intake of dairy, fruits & artificial sweetners & alc
MCC:
- Meds
- Disaccharidase def/Carb malabs: lactose intolerance; Carb malabs Dx by elimination trial for 2-3 wks or by H+ breath test
- laxative abuse (coule be osmotic/secretory)
- malabs syndromes
what are clinical manifestations of IBS
onset <30; F>M
abd pain (crampy/low abd) & irregular bowel habits
continuous or intermittent :
- abd distention,
- relief w/ BM,
- increase freq of stool w/ pain,
- loose stool w/ pain,
- mucus in stool
- sense of incomplete evacuation
What are the MCC of chronic diarrhea
When is it necessary to do further work up
medication, IBS, lactose intolerance
BUT presence of nocturnal diarrhea, wt. loss, anemia, fecal occult blood test (+) (FOBT) –> inconsistent w/ common causes & need further work up
What are characteristics of pancreatic insufficiency
Chronic pancreatitis, CF, or pancreatic CA
sig steatorrhea (bc malabs of triglycerides)–> wt loss, gaseous distention & flatulence, large, greasy, foul-smelling stools
digestion of proteins & carbs affected far lesser degree
micellar fxn & intestinal abs = normal –> signs nutrient or vit def rare
what are signs of malabs
loss of M mass or subQ fat
pallor
easy bruising (vit K def)
hyperkeratosis (vit A def)
bone pain due to osteomalacia (vit D def)
neurologic signs (peripheral neuropathy, ataxia)- Vit B12 & E def
what signs will make you want to further investigate bc they are incompatible w/ dx of IBS
- acute onset –> increase chance of organic dz, esp > 40–50 yo
- nocturnal diarrhea
- severe constipation or diarrhea
- hematochezia
- wt loss
- fever
- FHx CA, IBD, or celiac dz
what could be causes of malabs syndromes
small bowel mucosal disorders
pancreatic dz/insufficiency
bacterial overgrowth
lymphatic obstruction
what are the treatments and complications of C. diff
minimize transmission - wash hands w/ soap & water & use disposable gloves
D/C ABx if possible
complication: toxic megacolon/hemodynamic instablity –> perforation –> death
chronic use of laxatives can lead to..
melanosis coli
a benign hyperpigmentation of colon
how do you Dx C. diff
stool assay (for toxin A & B)
NAAT (PCR); fecal leukocytes -/+
CBC: leukocytosis: > 15K
imaging for severe/fulminant sxs - abd radiograph, noncontrast abd CT scan - look for evidence of colic dilation & wall thickening detection of perforation
flexible sigmoidoscopy: not in most pts; see pseudomembranous colitis - yellow adherent plaque; Bx - reveal epithelial ulcerations w/ “volcano” exudate of fibrin & neutrophils
what pts are at high risk fo acquiring C. diff
eldery, debilitated, immunocompromised
hospitalized (> 3 days)
on multiple ABx or prolonged Abx (>10 days): amplicilin, clindamycin, 3rd-gen cephalosporin, fluorquinolones
enteral tube feeding
PPI
chemotherapy
pt w/ IBD
what is apart of the Hx and PE of whipple dz
fever (intermittent, low grade), LAD, arthralgia
wt. loss, malabs, chronic diarrhea
hypoalbuminemia & edema, HF/valvular regurg, dementia, lethargy, coma, seizure, myoclonus, ophthalmoplegia or nystagmus
late finding = hypotension
LAD, heart murmur, peripheral joints enlarged/warm, peripheral edema
What are characteristics of ABx associated diarrhea
most cases not attributable to C. dff (DIFFERENTIATE FROM ABx associated COLITIS)
mild & self-limited
during the period of ABx exposure: dose related, resolves spotaneously after discontinuation of ABx (ex Augmentin)
doesn’t require any specific lab evaluation
what is the etiology of whipple dz
rare multi-system dz - infxn w/ gram (+) bacilli, not acid fast (tropheryma whipplei)
MC - white men 40-60s
source is unknown
how do you Tx/manage celiac dz
lifelong removal of all gluten
check: meds
Dietary supplements: (folate, Fe, zinc, Ca2+, and vit A, B6, B12, D, and E) –> initial stages of therapy but usually not required long-term
MC reason for treatment failure: is incomplete removal of gluten
may be associated w/ other autoimmune disorders
What are the extraintestinal sxs associated w/ celiac dz
- Fatigue
- Depression
- Fe def anemia
- Osteoporosis
- Short stature
- Delayed puberty
- Amenorrhea
- Reduced fertility
what pathogens are MC associated with chronic diarrhea
Protozoan: giardia, E. histolytica, cyclospora
intestinal nematodes: strongyloidiasis stercoralis
bacterial: c. diff
immunuocompromised/AIDs related - viral CMV, HIV; bacterial c. diff, mycobacterium avium complex; protozoal - micosporida, cryptosporidium, isospora beli & cyclospora
what are the sxs of pts w/ celiac dz
typical: wt loss, chronic diarrhea, dyspepsia, flatulence, abd distention/bloating, growth retardation, fatigue
atypical: dermatitis herpetiformis, Fe def anemia, osteoporosis
older kids & adults - less likely for serious malabs
how do you Dx and Tx lactase def
symptomatic improvement of lactose-free diet –> confirm by H+ breath test
pt finds “threshold” of intake that causes sxs
OTC lactase enzyme replacemnt - caplets/drops of lactase taken w/ milk products –> improve lactase abs
*pt that restrict/eliminate milk –> risk for osteoporosis (recommend Ca2+ supplements)
What is the DDx for acute diarrhea
Infectious: viral, bacterial, protozoal
Non-infectious (even if >14 days/<4 weeks)
- medication (MC): ABx, NSAIDs, antidepressants, chemo agents, antacids/laxatives (Mg2+)
- food allergies/intolerance
- artificial sweateners: Sorbitol, chewing gum
- tube feeding
- acute diverticulitis
- GVH dz
- ingestion of toxin
- chronic illnesses
What are clues and causes of secretory diarrhea
Clues: DOESNT improve w/ fasting, normal osmotic gap, increased intestinal secretion/decreased abs; high-vol watery diarrhea –> dehydration & electrolyte imbalance (hyponatremia, non-anion gap metoblic acidosis)
causes:
- endocrine tumors: stimulate intestinal/pancreatic secretion, zolinger ellison, carcinoid syndrome, medullary thryoid carcinoma
- bile salt malabs: stimulate colonic secretion; idiopathic, ileal resection, crohn ileitis, post-chlecystectomy
- factitious dirrhea: laxative abuse
- vilous adenoma
what is IBS characterized by
Altered bowel habits
Abd pain
Absence of detectable organic pathology
what are PE of celiac dz
may be normal in mild cases
signs of malabs
Dermatitis herpetiformis
= cutaneous variant of celiac disease
pruritic papulovesicles over the extensor surfaces of the extremities and over the trunk, scalp, and neck
what is the etiology, Hx and PE of constipation
impaction –> obstruct fecal flow more –> partial/complete large bowel obstruction
predisposing factors (opioids) sever psychiatric dz, prolonged bed rest, neurogenic disorders of the colon & spinal cord disorders
-decreased appetite, N/V, abd pain/distention, paradoxial “diarrhea” as liquid stool leaks –> overflow incontinence
DRE –> firm feces palpable
what is the etiology of celiac dz
immune response to gluten –> diffuse damage to proximal SI mucosa w/ malabs of nutrients (only 10% have sxs–> most cases undiagnosed. bc asymp)
n. european ancestry
sxs in pt w/ HLA-DQ2 and D8 class II molecules
gluten –> digested in intestal lumen into Glu-rich peptides –> glutamines are deamidated by tTG –> (-) glutamic acid residue; inappropriate T cell mediated activation –> destruction of mucosal enterocytes & humoral response –> Ab to gluten and tTG
how do you Dx IBS
chronic > 6 months (sxs for atleast 3 months before considering in DDx)
utilize rome IV clinical dx criteria
sigmoidoscopy & barium radiograph to exclude DDx (IBD, malignancy, giardiasis, lactase def, hyperthyroid)
what are the 3 types of clincal presentations of IBS
- spastic colon (chronic abd pain & constipation)
- alternating constipation and diarrhea
- chronic, painless diarrhea
what is the pathophys of IBS
visceral hyperalgesia to mechanoreceptor stimuli
- altered colonic motility (rest,w/ stress, cholinergic drugs, CCK)
- altered SI motility
- enhanced visceral sensation (lower pain threshold in response to gut distention)
- abn extrinsic innervation of the gut
may be post-infxn (ie after gastroenteritis)
i_ncreased frequency of psychological disturbances_ (depression, hysteria, OCD)
what is the MCC of ABx-associated colitis
C. diff
= anaerobic, gram (+), spore forming bacillus
cytotoxin (A & B) production
nosocomial, fecal-oral
what are characterisitics/classic sxs of malabs syndromes
wt loss
osmotic diarrhea
steatorrhea
nutritonal def
abd distention, weakness, M wasting, growth retardation
what is the prognosis of whipple dz
If untreated, the disease is fatal.
bc some neurologic signs may be permanent –> goal of tx =prevent progression
Pt must be followed closely after Tx for signs recurrence
What should be included in the initial diagnostic work-up for chronic diarrhea
routine lab tests
stool studies:
- osmotic/secretory;
- malabs;
- inflam fecal leukocytes, calprotectin, lactoferrin (may suggest IBD)
- infxn: ova/parasite, wet mount/fecal Ag (more sensitive) (= giardia & E. histolytica)
- acid-fast staining
endoscopic exam & mucosal Bx: colonoscopy w/ mucosal Bx to exclude IBD, colitis, colonic neoplasia; EGD w/ small bowel Bx: suspicion of small intestinal malabs; pts w/ advanced AIDS
If needed, what should be completed after initial work-up
- if malabs suspected:
- pancreatic insufficiency - fecal elastase < 100 mcg/g;
- chronic pancreatitis: calcification on plain abd radiograp
- Breath test: Small bowel bacterial overgrowth -noninvasive breath test (glucose/lactose) ; carb malabs: H+ breath test
- crohn’s dx, small bowel lymphoma, carcinoid, jejunal diverticula - SI imaging w/ barium, CT or MRI
- neuroendocrine tumors (rare/secretory) -serologic tests
- vasoactive intestinal peptide - VIPoma
- calcitonin - medullary thryoid carcinoma
- gastrin - zollinger-ellison
- urinary 5-hyrdoxyindoleacetic acid - carcinoid
what is the etiology, Hx and PE of lactase deficiency
lactase = brush border enzyme that hydrolyze lactose into glucose & galactose
other GI disodors (crohns, celiac, viral gastroenteritis, giardiasis, short bowel syndome & malnutrition) can affect proximal SI –> secondary lactose def
diarrhea, bloating, flatulence, abd pain after ingestion of milk
how do you tx/manage IBS
medication directed towards diarrhea, constipation, pain
avoid stress or precipitating factors (psychotherapy, exercise)
LOW FODMAPs: fermentable oligosac, disaccharides, monosaccharides & polyols (fermentable carbs may improve sxs)
frutose, wheat-based products, sorbitol, raffinose
What is the DDx for chronic diarrhea
- meds
- IBS
- lactose def/intolerance
- chronic infxn
- malabs conditions
- overflow incontinence/fecal impaction
What are the common medicinal offenders that can cause diarrhea
cholinesterase inhibitors
SSRIs
angiotensin II receptor blockers
PPI
NSAIDs
Metformin
allopurinol
how do you Dx and Tx Whipple
Endoscopy w/ Duodenal Bx - periodic acid Schiff (PAS)- (+) macrophages w/ bacillus
Lab findings: evidence of malabs & steatorrhea
Also could use: (PCR) or immunohistochemistry of duodenal Bxor extraintestinal fluids (cerebrospinal, synovial) or tissue (LN, synovium, endocardium)
ABx therapy - dramatic improvement w/i several weeks; prefer drugs that cross BBB
