diarrhea and IBS

Question 1

diarrhea

Answer 1

increased frequency and decreased consistency of fecal discharge compared to an individual’s normal bowel patterns
episodes usually begin abruptly and subside within 1-2 days without treatment
often a symptom of a systemic disease

Question 2

acute diarrhea

Answer 2

less than 14 days duration

usually caused by an infectious process

Question 3

persistent diarrhea

Answer 3

over 14 days in duration

Question 4

chronic diarrhea

Answer 4

over 30 days in duration

Question 5

chronic idiopathic diarrhea

Answer 5

persistently loose stools for over 4 weeks without identifiable cause*, and occurring in absence of systemic illness, the diarrhea is second degree in nature and does not respond to antibiotics, but resolves in several months

Question 6

infectious causes of diarrhea

Answer 6

bacterial: shigella, salmonella, campylobacter, staphylococcus, e coli***
viral: norovirus, rotovirus (most common)

Question 7

diarrhea etiology:

Answer 7

not routinely reported to CDC
not uncommon in daycare centers and LTCF
chronic diarrhea impacts 5% of US population
leading cause of childhood illness and death in developing countries

Question 8

diarrhea physiology

Answer 8

9 L of fluid enter the proximal small intestine every day
1 L of chyme typically enters the colon and is reduced to 100 mL
**if small intestine water absorptive capacity is exceeded, chyme overloads the colon, resulting in diarrhea
diarrhea may result from an imbalance of secretion and reabsorption of fluids and electrolytes
segmenting contractions delay passage and mix intestinal contents allowing for greater absorption

Question 9

secretory diarrhea

Answer 9

characterized by a change in active ion transport by either a decrease in sodium absorption or an increase in chloride secretion into the lumen and water follows
pancreatic tumors, unabsorbed fat, laxatives, bacterial toxins
*large stool volumes (over 1 L/day)
*not altered by fasting

Question 10

osmotic diarrhea

Answer 10

caused when poorly absorbed substances draw in and retain intestinal fluids in the lumen
malabsorption syndrome
lactose intolerance
administration of divalent ions (Mg containing antacids)
consumption of poorly soluble CHOs (lactulose, sorbitol)
*causes if patient resorts to fasting state

Question 11

exudative diarrhea

Answer 11

diarrhea second to inflammatory diseases of the bowel
IBD discharge mucus, proteins, and blood into gut
large stool volumes

Question 12

altered (increased) intestinal transit diarrhea

Answer 12

decrease time of exposure between intestinal epithelium and chyme leads to irregular absorption and secretion
typically caused by bowel restriction or promotility medications such as metoclopramide
altered motility d/t neuropathy from DM

Question 13

causes of drug induced diarrhea

Answer 13

excessive laxatives
magnesium containing antacids
antineoplastics
sorbitol containing products*
NSAIDs
misoprostol
metoclopramide
lithium
antimicrobials (clindamycin, broad spectrum (cephalosporins))

Question 14

nonpharm treatment of diarrhea

Answer 14

rehydration with pedialyte, gatorade
d/c solid foods and dairy products x 24 hours ?
probiotics? yogurt?
mild, digestible, low-residue diet x 24 hours
BRAT diet*

Question 15

desired outcomes when treating diarrhea

Answer 15

manage the diet
prevent excessive water, electrolyte and acid-base disturbances
*provide symptomatic relief
treat curable causes
manage secondary causes

Question 16

treating acute diarrhea

Answer 16

symptoms lasting fewer than 3 days
most cases can be treated with OTC products
no fever or systemic sxs: fluid and electrolyte replacement, loperamide, diphenoxylate or absorbent, diet
fever or systemic symptoms: check feces for WBC/RBC/ ova and parasites
negative: symptomatic therapy
positive: use appropriate antibiotic and systematic therapy

Question 17

treating persistent/chronic diarrhea

Answer 17

symptoms lasting over 14 days*
patients experiencing symptoms for greater than 14 days should always be referred to a physician**
if idiopathic, some patients may require chronic management with loperamide or another agent
possible causes: GI infection, IBD, malabsorption, secretory hormonal tumor, drug, mobility disturbance
select appropriate diagnostic studies
no dx: symptomatic therapy - replete hydration, d/c potential drug inducer, adjust diet, loperamide or absorbent
diagnosis: treat specific cause

Question 18

traveler’s diarrhea

Answer 18

most cases are infective, primarily caused by bacteria
presents as acute, watery diarrhea
duration: 2-3 days
treatment: **most cases can be controlled by oral rehydration solutions paired with an anti-motility agent; antimicrobials are effective but are rarely used (resistance)
prevention: drink bottled water and drinks, be sure fruits and vegetables are properly washed and prepared, consider peptobismol 1-4x daily

Question 19

drug induced diarrhea

Answer 19

decreased transit time leading to irregular absorption and secretion, alteration bowel flora (antimicrobials)
may range from a mild inconvenience to a life-threatening antibiotic associated
duration depends on causative agent
tx: d/c offending agent when possible**, oral rehydration solutions and anti-motility agents may be needed

Question 20

antimotility drugs

Answer 20

works by activating the mu opioid receptors on the smooth muscle of the bowel to reduce peristalsis and increase segmentation
loperamide, diphenoxylate, difenoxin, codeine (15-30 mg q6h PRN)

Question 21

loperamide

Answer 21

imodium
4 mg initially, then 2 mg after each loose stool
NTE 16 mg/day
recent concern about potential arrhythmias from excessive doses (abuse)

Question 22

diphenoxylate/atropine

Answer 22

usually combined with atropine (ACh, prevents abuse due to limits)
lomotil
5 mg (2 tabs) QID
NTE 20 mg/day
Rx only

Question 23

diphenoxin/atropine

Answer 23

motofen
2 mg (2 tabs) initially, then 1 with each loose stool
NTE 8 tabs/day

Question 24

absorbents

Answer 24

used for some patients with chronic diarrhea when they have trouble forming solid stools
effectiveness unproven
oral, non-absorbed agents
kaolin-pectin (now used in animals), attapulgite, polycarbophil, metamucil (powder)

Question 25

antisecretory agents

Answer 25

act by reducing secretions in the gt
bismuth subsalicylate (peptobismol, kaopectate): has also shown to have antimicrobial and anti-inflammatory effects, 2 tabs or 30 ml q30-60 min PRN, up to 8 doses/day, avoid in patients who should not take salicylates (anticoag)
enzymes (lactase)

Question 26

irritable bowel syndrome

Answer 26

syndrome: combination of symptoms, NOT disease
characterized by abdominal pain or cramping and changes in bowel function (bloating, gas, diarrhea, constipation)
up to one in five american adults has IBS - chronic
women more often than men
accounts for more than 1/10 doctors visits
for most people, s/sxs are mild
its a relapsing/remitting disease
*only a small percentage of people with IBS have severe s/sxs
IBS doesn’t cause inflammation or changes in bowel tissue or increase risk of colorectal cancer

Question 27

subtypes of IBS

Answer 27

IBS-C - hard or lump stools at least 25% of the time, loose or watery stools less than 25% of the time
IBS-D - loose or watery stools at least 25% of the time, hard or lumpy stools less than 25% of the time
IBS-M (mixed IBS) - hard or lumpy stools at least 25% of the time and loose or watery stools at least 25% of the time
IBS-U (unsubtyped IBS) - hard or lumpy stools less than 25% of the time and loose or watery stools less than 25% of the time

Question 28

s/sx of IBS

Answer 28

abdominal pain or cramping, gas, bloated feeing
diarrhea or constipation - people with IBS may experience alternating bouts of constipation and diarrhea
mucus in the stool

Question 29

treatment of IBS-C

Answer 29

1. manage stress plus patient education
   2diet: increase fiber and fluid intake, avoid food that in crease sxs, gluten free?, low FOD-MAP?,
2. add bulk-laxative/soluble fiber
3. consider adding antispasmotics or AChs to relieve painful bowel spasms
4. consider lubiprostone or linaclotide for treatment of both constipation and abdominal pain
5. consider TCA or SSRI for pain and depression
6. consider serotonin-4 agonist (tegaserod)

Question 30

treatment of IBS-D

Answer 30

1. manage stress plus patient education
2. diet: lactose and caffeine free, avoid foods that increase symptoms
3. add loperamide or other antispasmotic (loperamide may not relieve pain or bloating)
4. replace with eluxadolin (dec. pain, frequency and urgency)
5. consider rifaximin
6. add serotonin-3 antagonist (alosetron)
7. consider TCA or SSRI for pain, depression and anxiety

Question 31

alosetron

Answer 31

5HT-3 antagonist
access resticted by REMS
begin with 0.5 mg BID x 4 weeks
may increase to 1 mg BID after 4 weeks if necessary - higher doses are not proven effective
medications should be stopped if constipation develops

Question 32

lubiprostone

Answer 32

amitiza
indicated for IBS-C in women (studies) over 18 - can use in all adults
8 mcg BID
diarrhea/nausea/HA
$293/month
avoid in pregnancy
should be reserved for: patients who do not respond to or tolerate other laxative

Question 33

linaclotide

Answer 33

linzess
indicated for IBS-C
290 mcg QD
take on an empty stomach at least 30 minutes before the first meal of the day
$273/mo
monitor for diarrhea*

Question 34

tegaserod

Answer 34

5HT-3 agonist
indicated for women with IBS-C
begin with 6 mg BID x4-6 weeks, tx may be extended for another 4-6 weeks if patient responds
restricted use only* higher risk of CV disorders after initial marketing
previously removed from US market

Question 35

other agents used in IBS

Answer 35

dicyclomine - antispasmotic, 20 - 40 mg q6h, take 30-60 min before meals
hyoscamine - ACh, 0.125-0.25 mg PO/SL q4h PRN, max: 1.5 mg/day
rifaximin - IBS-D, MOA is unknown but thought to be related to changes in GI flora, 550 mg TID x 14, patient who experience recurrence can be treated up to 2x with same regimen, may not be as effective at relieving other IBS sxs
eluxadoline - mu receptor agonist and delta opioid antagonist, decreases bowel contractions, slows motility/relieves pain, 75-100 mg BID WF, IBS-D, 1150/mo
peppermint oil - EC SR microspheres, menthol, 1-2 caps PRN up to TID, 30 min AC or PC