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Flashcards in Constipation and Diarrhea Deck (40)

What is constipation?

- passage of stool infrequently or with difficulty
- stool frequency of less than 3 per week due to:
straining, hard stool or incomplete evacuation


Epidemiology of constipation?

- adults: 10%
- elderly: 20-30%:
22% in elderly living in community
50% in hospice
63% in hospitalized elderly
- women more than men


Etiologies of constipation?

- most common: lifestyle
- inadequate fiber in diet: fiber promotes normal transit time, frequent stools, and lower use of laxatives
- inadequate hydration
- inactivity


Meds that cause constipation?

- opiates***/narcotics
- antidepressants
- CCBs
- antipsych
- antiparkinsonian agents
- anticholinergics
- Ca, Fe supplements
- antispasmodics
- antacids (Ca and Al)


Structural abnormalities that may cause constipation?

- carcinoma
- ischemia
- volvulus
- megacolon
- anorectal disorders: prolapse, rectocele, pelvic floor dysfxn (nerve disorder, delivery)


Metabolic causes of constipation?

- hypokalemia
- hypomagnesemia
- hypothyroidism****
- hyperparathyroidism
- porphyria: genetic hemoglobin disorder
- addison's disease (going to have diarrhea most likely)
- hypercalcemia


Neurologic causes of constipation?

- parkinson's
- MS
- autonomic neuropathy
- Hirschprung disease
- chagas disease (protozoan, spread by kissing bugs)
- spinal cord lesions
- Cerebrovascular disease


Systemic causes of constipation?

- amyloidosis
- scleroderma
- polymyositis
- pregnancy


Surgical causes of constipation?

- abdominal
- pelvic
- colonic
- anorectal


Psych causes of constipation?

- depression (always ask about bowel changes)
- eating disorders


Exam of pt with constipation? Who should be further evaluated and tx?

- 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
wt loss
positive FOBT


Eval of constipation?

- KUB, barium enema or colonoscopy (best bet)
- blood tests:
CBC: anemia -detect colorectal neoplasm


When is a colonic transit study done?

- to observe transit time in pts with refractory constipation not responding to conservative measures


Most impt form of management in constipation?

- 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


Tx of constipation?

stool softeners (surfactants):
-colace (docusate sodium)
- docustae calcium

- 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!


What is diarrhea?

- 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


Osmotic diarrhea PP?

- non-absorbable substance draws out excess water into intestines and increases stool wt and volume


Secretory diarrhea PP?

- mucosal secretion of fluid and electrolytes secondary to bacterial enterotoxins, neoplasms, or exotoxins


Motility diarrhea PP?

- 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


Diff b/t acute, persistent and chronic diarrhea?

- 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


Acute and chronic diarrhea clinical manifestations?

- 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


Causes of acute infectious diarrhea?

- 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


Causes of noninfectious acute diarrhea?

- drugs
- food allergies
- disease states such as thyrotoxicosis and carcinoid syndrome


Indications for dx eval of acute diarrhea?

- 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)


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


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)


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


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


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


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


Chronic infections - can cause chronic diarrhea?

- AIDs related, CMV, HIV
- bacterial: C diff, mycobacterium avium complex
- protozoal: Giardia, entamoeba histolytica, microsporida, cryptosporidium


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


Fecal analysis: fecal leuks finding?

- presence indicated bowel mucosal inflammation, which occurs in invasive bacterial enteritis and UC


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


Stool for culture and sensitivity - findings?

- enterococcus
- e-coli
- clostridium
- tx with cipro


Stool for ova and parasites - findings?

- salmonella
- shigella
- giardia


C-diff toxin assay findings?

- c-diff multiplies and releases toxin that causes necrosis of colonic epithelium which causes diarrhea


Fecal fat findings - etiologies?

- quantitative stool fat:
confirms steatorrhea
whipples dz


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


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