Lecture 2: Diarrhea/Constipation Flashcards
In what demographic is especially diarrhea concerning in?
Infants
What are the 3 duration types of diarrhea?
- Acute < 2 weeks
- Persistent 2-4 weeks
- Chronic > 4 weeks
What is the primary cause of acute diarrhea?
Infectious agents
What are the two ways acute diarrhea agents are transmitted?
- Fecal oral transmission
- Disturbance of GI flora due to ABX
Who are the 5 high risk groups for acute diarrhea?
- Traveler’s (E. coli + giardia)
- Food at a picnic, banquet, or restaurant
- Immunodeficient
- Daycare attendees and their family
- Institutionalized persons
How does inflammatory diarrhea present?
- Bloody
- Feverish
- LLQ Cramps
Dysentery
Need stool cultures
How does noninflammatory diarrhea typically present?
- Watery
- Nonbloody
- Periumbilical cramps
We only evaluate if severe or > 7 days.
How does a small bowel infection typically present in terms of diarrhea?
- Abd cramping
- Bloating, gas
- Wt loss
- Watery diarrhea
Fever is rare
What is the MCC of watery diarrheas?
Enteric viruses
What is the MCC of large, inflammatory diarrheas?
Bacterial pathogens
Large bowel infection
Bacteria are bigger than viruses = bigger diarrhea?
What are the only virus and only protozoan that cause inflammatory idarrhea?
- CMV
- Entamoeba histolytica
If acute diarrhea present 1-6 hrs post exposure, what are the likely culprits?
- Staph
- B Cereus
What pathogens cause diarrhea over a 1 week after exposure?
- Cryptosporidium
- Giardia
What are the likely pathogens if the history suggests exposure to a daycare, mountain stream, or community swiming pool?
- Giardia
- Cryptosporidium
- Entamoeba
How are norovirus and enteric viruses typically transmitted?
Household/community spread
When does C diff associated diarrhea typically occur?
2 weeks - 1 month post ABX therapy
What are the most common ABX implicated in C diff diarrhea?
- Fluoroquinolones
- Clindamycin
- Cephalosporins
- PCNs
What would prompt us to hospitalize a patient for diarrhea?
- Severe dehydration
- Organ failure
- Marked abdominal pain
- AMS
What is the workup for most acute noninflammatory diarrheas?
* No diagnostic investigation!
* 90% are self-limited.
If we have persistent diarrhea, what labs do we order?
- Fecal leukocyte
- Stool culture
- Stool for O & P
- Stool for C. diff
What is the recommended diet for someone with persistent diarrhea?
- Bananas
- Rice
- Applesauce
- Toast
BRAT
Also soup and crackers
What is the home DIY Liquid IV recipe?
- 1/2 tsp salt
- 1 tsp baking soda
- 8 tsp sugar
- 8 oz OJ
- 1L water dilution
How does loperamide work?
GI Opioid agonist that inhibits peristalsis.
Contraindicated in inflammatory diarrhea.
How does pepto-bismol work?
- Reduce gut secretions
- Avoid in preggos and children.
How does diphenoxylate/atropine work?
Anticholinergic
Contraindicated in acute and inflammatory diarrhea.
RISK: TOXIC MEGACOLON
What are the empiric ABX therapy for diarrhea?
- First-line: Cipro or Levofloxacin for 3 days
- Alternatives: Bactrim DS or Doxy
What are osmotic diarrheas and what resolves it?
- Carb malabsorption
- Laxative abuse
- Malabsorption
- RESOLVES DURING FASTING
Resolution from fasting = osmotic diarrhea
What causes secretory disorders in chronic diarrhea?
- Endocrine tumors
- Bile salt malabsorption
NOT RESOLVED BY FASTING
What are the two common inflammatory conditions that can result in chronic diarrhea?
- Ulcerative colitis
- Crohn disease
Subtypes of IBD
What characterizes a malabsorptive condition?
- Wt loss
- Osmotic diarrhea
- Steatorrhea
- Nutritional deficiencies
What is the MCC of chronic diarrhea in young adults?
IBS
What kind of disorder is IBS and how does it present?
Motility disorder.
- Lower abd pain
- Altered bowel habits
- NO evidence of serious organic disease
What are the 5 MC pathogens associated with chronic diarrhea?
- Giardia
- E. histolytica
- Cyclospora
- Intestinal nematodes
- C. diff
What two systemic conditions can cause chronic diarrhea?
- Thyroid disease (hyper = hypermotility)
- Diabetes
What stool appearance is more suggestive of malabsorption? Inflammatory?
- Malabsorption: Greasy, malodorous
- Inflammatory: Blood or pus
What specific serologic test might we look for in chronic diarrhea?
Celiac disease serology
What is the MOA of loperamide and diphenoxylate?
- MOA: Opioid receptor agonists to slow peristalsis.
When should you NOT use loperamide or diphenoxylate?
- Bloody/inflammatory diarrhea
- C. diff related diarrhea
- Pts < 2 yrs
Anything that slows gut motility is a nono in bloody diarrhea
What is the MOA of bismuth and common reactions to it?
- MOA: Reduces secretions, some antimicrobial effect.
- Causes black stool and black tongue
What is octreotide and how does it work?
- Used for chronic, secretory diarrhea
- Inhibits intestinal fluid secretion and stimulates absorption.
Secretory diarrhea = Does NOT resolve with fasting.
Secretory disorders are characterized by increased secretion and poor absorption, so octreotide does the opposite.
What is the main concern with using octreotide?
Inhibition of many hormone productions.
Caution in DM, thyroid, pancreas, kidney, liver, or arrhythmias.
What is cholestyramine used for and how does it work?
- Indications: Chronic secretory or malabsorptive diarrhea
- Binds intestinal bile acids
Also lowers cholesterol!
chole = bile acid and cholesterol
What do hyoscyamine and dicyclomine do?
- Relaxes intestinal smooth muscle
- Inhibits spasms and contractions
- Mainly used for diarrhea associated with IBS
Antispasmodics
Who should antispasmodics NOT be used in?
- Toxic megacolon
- IBD
Who is constipation MC in?
Elderly women
What is constipation?
- Infrequent stools < 3 a week
- Hard stools
- Excessive straining
- Sense of incomplete evacuation
How long is average colonic transit time?
35 hours
What are the two MCC of constipation?
- Inadequate fiber or fluid intake
- Poor bowel habits
What would prompt us to further workup constipation?
- Severe constipation or age over 50.
- Hematochezia, wt loss, positive FOBT
- FMHx of colon cancer or IBD
- Refractory constipation
What does fiber do?
Promotes intestinal motility by absorbing water into stool.
What exactly do stool softeners do?
Emollient that covers stool to soften it.
What is the concern with using mineral oil as a stool softener?
Absorption of key nutrients.
What do osmotic laxatives do?
- Increase secretion of water into the lumen
- Soften stool and promote defecation
- Works within 24 hours
What is used as a bowel cleanser and when?
- Osmotic laxatives
- Polyethylene glycol (PEG)
- Mag citrate
- Sodium phosphate (fleet enema)
- Prior to colonoscopy or bowel surgery
When are stimulant laxatives used and what do they do?
Bisacodyl, Senna, Cascara
- For patients with poor response to osmotic agents.
- Used as a rescue agent, not daily
- Stimulation of fluid secretion and colonic contraction
What are the main concerns with using stimulant laxatives?
- Not for long-term or daily use
- Electrolyte abnormalities
What is the order of preference in pharmacologic managment of constipation?
- Fiber supplements
- Stool softeners
- Osmotic laxatives
- Stimulant laxatives
What 5 conditions may predispose someone to fecal impaction?
- Medications
- Severe psychiatric disease
- Prolonged bed rest
- Neurogenic disorders of the colon
- Spinal cord disorders
How does fecal impaction usually present clinically?
- Decreased appetite
- N/V
- Abd pain and distension
- Paradoxical diarrhea
What is the initial management for a fecal impaction?
- Enemas
- Digital disimpaction
