Constipation and Diarrhea Flashcards
1
Q
What is constipation?
A
- passage of stool infrequently or with difficulty
- stool frequency of less than 3 per week due to:
straining, hard stool or incomplete evacuation
2
Q
Epidemiology of constipation?
A
- adults: 10%
- elderly: 20-30%:
22% in elderly living in community
50% in hospice
63% in hospitalized elderly - women more than men
3
Q
Etiologies of constipation?
A
- most common: lifestyle
- inadequate fiber in diet: fiber promotes normal transit time, frequent stools, and lower use of laxatives
- inadequate hydration
- inactivity
4
Q
Meds that cause constipation?
A
- opiates***/narcotics
- antidepressants
- CCBs
- antipsych
- antiparkinsonian agents
- anticholinergics
- Ca, Fe supplements
- antispasmodics
- antacids (Ca and Al)
5
Q
Structural abnormalities that may cause constipation?
A
- carcinoma
- ischemia
- volvulus
- megacolon
- anorectal disorders: prolapse, rectocele, pelvic floor dysfxn (nerve disorder, delivery)
6
Q
Metabolic causes of constipation?
A
- hypokalemia
- hypomagnesemia
- hypothyroidism**
- hyperparathyroidism
- porphyria: genetic hemoglobin disorder
- addison’s disease (going to have diarrhea most likely)
- hypercalcemia
7
Q
Neurologic causes of constipation?
A
- parkinson’s
- MS
- autonomic neuropathy
- Hirschprung disease
- chagas disease (protozoan, spread by kissing bugs)
- spinal cord lesions
- Cerebrovascular disease
8
Q
Systemic causes of constipation?
A
- amyloidosis
- scleroderma
- polymyositis
- pregnancy
9
Q
Surgical causes of constipation?
A
- abdominal
- pelvic
- colonic
- anorectal
10
Q
Psych causes of constipation?
A
- depression (always ask about bowel changes)
- eating disorders
11
Q
Exam of pt with constipation? Who should be further evaluated and tx?
A
- full hx
- full physical exam: DRE: stool for occult blood
- in pts less than 50 with no alarm sxs: may start empiric tx
- further tx should be performed on pts with any of following:
over 50
severe constipation
signs of organic disorder
hematochezia
wt loss
positive FOBT
12
Q
Eval of constipation?
A
- KUB, barium enema or colonoscopy (best bet)
- blood tests:
glucose
CBC: anemia -detect colorectal neoplasm
thyroid
Ca2+
Mg+
Phosphorous
13
Q
When is a colonic transit study done?
A
- to observe transit time in pts with refractory constipation not responding to conservative measures
14
Q
Most impt form of management in constipation?
A
- PREVENTION!!!!
- pt education:
1. exercise: key stimulus to colon peristalsis and defectation, encourage and enable pt to be mobile or be in upright position
2. fluid intake: constipated stools are low in water content
3. fiber intake: acute constipation low on fiber diet, dont give in chronic constipation- just makes it harder, responds poorly
15
Q
Tx of constipation?
A
stool softeners (surfactants):
- colace (docusate sodium)
- docustae calcium
laxatives:
- bulk laxatives: psyllium, methylcellulose, fibercon (polycarbophil), benefiber (wheat dextran)
- osmotics**: lactulose, sorbitol, polyethylene glycol, Mg citrate, Mg sulfate (caution in renal impairment)
Stimulant laxatives: bisacody, senna
-bowel becomes dependent on stimulants, don’t use chronically
opioid receptor antagonist: methylnaltrexone: approved for palliative care pts, pts on chronic opiod tx, doesn’t effect central analgesia
digital disimpaction: refer,!! You or the pt shouldn’t be doing this!
16
Q
What is diarrhea?
A
- increase in daily stool wt above 200-300 g/24 hrs
- clinically: increase in stool liquidity and/or frequency
- in developed countries:
normal stool wt of an adult human is less than 200 g/d - stool water accounts for 60-85% of wt
- normal bowel frequency ranges from 3x a week to 3x a day
- greater than 3x a day is considered abnormal
17
Q
Osmotic diarrhea PP?
A
- non-absorbable substance draws out excess water into intestines and increases stool wt and volume
18
Q
Secretory diarrhea PP?
A
- mucosal secretion of fluid and electrolytes secondary to bacterial enterotoxins, neoplasms, or exotoxins
19
Q
Motility diarrhea PP?
A
- food isn’t mixed properly, digestion is impaired and motility is increased, secondary to resection of small intestine, surgical bypass of an area of intestine or diabetic neuropathy
20
Q
Diff b/t acute, persistent and chronic diarrhea?
A
- acute: less than or equal to 14 days
- persistent: more than 14 days in duration
- chronic: AGA suggests that chronic diarrhea should be defined as decrease in fecal consistency lasting 30 days or more
21
Q
Acute and chronic diarrhea clinical manifestations?
A
- acute is usually due to infections with viruses and bacteria and are self limited:
fever, cramping pain, if severe, can get dehydrated** esp in kids or elderly - chronic usually secondary to IBS or IBD, or malabsorption syndromes
22
Q
Causes of acute infectious diarrhea?
A
- viral:
norovirus, rotavirus, adenovirus, astrovirus - bacterial:
salmonella, campylobacter (GBS), shigella, enterotoxigenic E coli, C diff - protozoa: (use wet mount):
cryptosporidium: most common parastic cause of acute food borne diarrheain US, giardia, cylcospora, entamoeba
23
Q
Causes of noninfectious acute diarrhea?
A
- drugs
- food allergies
- disease states such as thyrotoxicosis and carcinoid syndrome
24
Q
Indications for dx eval of acute diarrhea?
A
- profuse watery diarrhea with signs of hypovolemia
- passage of many small volume stools containing blood and mucus
- bloody diarrhea
- temp at or greater than 101.3 (38.5 C)
- passage of 6 or more unformed stools per 24 hours or a duration of illness of more than 48 hrs
- severe abdominal pain
- hospitalized pts or recent use of abx
- diarrhea in elderly (older than 70) or immunocompromised
- systemic illness with diarrhea, esp in pregnant women (listeriosis should be suspected)
25
Etiologies of chronic diarrhea?
- meds: SSRIs, ARBs, PPIs
- osmotic: increased osmotic gap - laxative abuse
- secretory
- inflammatory: crohns, UC
- malabsorptive: steatorrhea
- motility disorders: exercise or stress induced
- chronic infections
26
Clues that cause of chronic diarrhea is osmotic? Meds?
- stool vol decreases with fasting, increased stool osmotic gap
- meds: antacids, lactulose, sorbitol
- disaccharidase deficiency: lactose intolerance
- facticious diarrhea: Mg (antacids, laxative)
27
Clues that cause of chronic diarrhea is secretory? Causes?
- clues: large vol - over 1 L/day, little change with fasting, normal stool osmotic gap
- hormonally mediated: carcinoid, medullary carcinoma of thyroid (calcitonin), zollinger-ellison syndrome (gastrin)
- factitious diarrhea: laxative abuse
- villous adenoma: secretes K+ rich fluid
- bile salt malabsorption: ileal resection, crohn ileitis, postcholecystectomy
- meds
28
Clues of inflammatory causes of diarrhea? Causes?
- clues: fever, hematochezia, abdominal pain
- IBD: UC or crohns
- malignancy: lymphoma, adenocarcinoma (w/ obstruction and pseudodiarrhea)
- radiation enteritis
29
Clues of malasbsorption cause of diarrhea? Causes?
- wt loss, abnorm lab values, fecal fat greater than 10 g/24 hrs
- small bowel mucosal disorders: celiac sprue, tropical sprue, whipple disease, eosinophilic gastroenteritis, small bowel resection, crowns
- lymphatic obstruction: lymphoma, carcinonid, infectious (TB, MAI), kaposi sarcoma, sarcoidosis, retroperitoneal fibrosis
- pancreatic disease: chronic pancreatitis, pancreatic carcinoma
- bacterial overgrowth: motility disorders - diabetes, vagotomy, scleroderma, fistulas, small intestinal diverticula
30
Motility disorders - that cause chronic diarrhea? Clues?
- clues: systemic disease or prior abdominal surgery
- postsurgical: vagotomy, partial gastrectomy, blind loop with bacterial overgrowth
- systemic disorders: scleroderma, DM, hyperthyroidism
- IBS
31
Chronic infections - can cause chronic diarrhea?
- AIDs related, CMV, HIV
- bacterial: C diff, mycobacterium avium complex
- protozoal: Giardia, entamoeba histolytica, microsporida, cryptosporidium
32
Workup of diarrhea? fecal analysis?
- hx: travel, longevity of sxs, family hx, food intake and relationship to onset
- fecal analysis:
fecal leukocytes
fecal occult blood
fecal fats
enteric pathogen cultures
C diff toxin
ova and parasites
- other labs: TSH, CBC, CMP with LFTs, ESR, CRP
33
Fecal analysis: fecal leuks finding?
- presence indicated bowel mucosal inflammation, which occurs in invasive bacterial enteritis and UC
34
Fecal occult blood test findings?
- immunochemical tests for fecal blood (FIC or iFOBT) for hemoglobin are more specific than guaiac tests b/c they respond only to human globin and don't detect upper GI bleeding
- hemoccult: + result obtained on multiple specimens performed on excessive days
35
Stool for culture and sensitivity - findings?
- enterococcus
- e-coli
- clostridium
- tx with cipro
36
Stool for ova and parasites - findings?
- salmonella
- shigella
- giardia
37
C-diff toxin assay findings?
- c-diff multiplies and releases toxin that causes necrosis of colonic epithelium which causes diarrhea
38
Fecal fat findings - etiologies?
```
- quantitative stool fat:
confirms steatorrhea
sprue
crohn's
whipples dz
```
39
When should an endoscopic exam and bx be done? What other studies are done?
- colonoscopy with mucosal bx to exclude IBD, microscopic colitis, and colonic neoplasia
- upper endoscopy when small intestine disorder is suspected such as celiac sprue or whipple disease
- other studies:
24 hr stool collection (IBS, malabsorption)
other imaging
40
Tx of diarrhea?
- fluid replacement
- avoid fatty foods
- abx therapy: shigelosis, traveler's diarrhea, pseudomembranous enterocolitis, cholera, parasitic diseases (tx of choice: cipro, or TMP SMX)
- bismuth subsalicylate (pepto : don't give to kids)
- opiate antidiarrheal agents: diphenoxylate (lomotil) and loperamide (immodium): for mid to mod secretory diarrhea
- cholestyramine (questran): diarrhea caused by ileal bile salt malabsorption
