Approach to Diarrhea

Question 1

56 yr/old female with HTN and fibromyalgia. • Previously “normal” BMs until 3 months ago. • Over past 3 months has 3 loose stools daily with urgency, preceded by crampy abdominal pain that his relieved with the BM. • Weight is up 20 lbs over the past 6 months. • No blood, mucus, fevers or chills.

Answer 1

Not diarrhea

Question 2

• 21 yr/old college student who recently returned from spring break in Cancun. • Having crampy, watery, non-bloody BMs up to 6-8 times a day for the past 3 days. • Poor appetite and feels “run down”.

Answer 2

Yes diarrhea

Question 3

• 83 yr/old female with osteoporsis who is otherwise healthy. • Complains of diarrhea over the past 3 years. • Having a single loose BM after a formed BM every morning, fine for the remainder of the day. • Denies incontinence, urgency or blood in her stool. • Weight and appetite are stable.

Answer 3

no she doesn’t

Question 4

• 30 yr/old male with his of liver transplant for Primary Sclerosing Cholangitis who developed progressively worsening diarrhea over the past 3 months. • Started with 4-5 watery stool, but now up to 10-15 BMs per day with blood in >50%. • Having nocturnal BMs and episodes of fecal incontinence about once a week.

Answer 4

yes

Question 5

Diarrhea_____ grams or____ mL per 24 hour period.

– Difficult to accurately measure • Patient has to be eating • High fiber diet can easily get over 300 gm/d • Does not factor in consistency or frequency

Answer 5

> 200 or 200 mL

Question 6

Inadequate nutrient absorption

– Associated with steatorrhea

– Relieved by fasting.

Answer 6

Malabsorptive diarrhea

Question 7

– Due to inflammatory disease

– Purulent, bloody stools

– Continue during fasting

Answer 7

Exudative diarrhea

Question 8

To have malabsorptive diarrhea, need to have disturance in at least one of four phases

Answer 8

1. Intraluminal digestion – Break down of proteins, carbohydrates, and fats into absorbable forms
2. Terminal digestion – Hydrolysis of carbohydrates and peptides by disaccharidases and peptidases in the brush border
3. Transepithelial transport – Defects in transport of nutrients, fluid, and electrolytes across the small intestinal epithelium
4. Lymphatic transport – Defects in of lipid absorption.

Question 9

Practical definition of normal bowel movemnts

of diarrhea

Answer 9

Normal Bowel Movement: – One BM every three days to 3 BMs every day

• Diarrhea – More than three lose/watery stools per day – Or a clear increase in frequency and decrease in consistency over baseline.

Question 10

Clues for ‘Real’ Diarrhea

Answer 10

Consistency, urgency, incontience, nocturnal BMs, Flatuphobia

Question 11

Where is water absorbed in the intestines

Answer 11

10L come out of stomach

6 L from JJ

2. 5L from Ileum
3. 4 from large intestine

Question 12

Where do we absorb fat sobule vitamins?

lipids?

bile salts?

Answer 12

duodenum/jj

lipids in both duodenum and jj

bile salts in the ilium

Question 13

what is abosorbed in the large intestine

Answer 13

water

vit k and biotin

Sodium, Chloride, potassium

Question 14

Functions to absorb most water, nutrients, minerals, sugars and protein.

Answer 14

small bowel

Question 15

Issues here causes:

Watery diarrhea, large volume and less frequent.

• Abdominal cramping, bloating, gas and weight loss.

Answer 15

Small bowel

Question 16

Evidence of malabsorption, vitamin or nutrient deficiencies.

• Fever is rare
• Rare stool WBCs or occult blood

Answer 16

small bowel issues

Question 17

Functions as storage and some fluid/electrolyte absorption

Answer 17

large bowel

Question 18

Frequent, small, regular stools • Tenesmus (rectal “dry heaves”) • Painful BM

Answer 18

large bowel

Question 19

what do we see in stool in large bowel issues?

Answer 19

Fever, bloody, mucoid stools • RBCs and WBC on stool smear.

Question 20

Neither the small intestine nor the colon can maintain an____ gradient again serum

Answer 20

osmotic

Question 21

Unabsorbed ions that remain in the lumen – Osmotically active ions act to pull water into the lumen of the bowel – Maintain an intraluminal osmolality =

Answer 21

290 mOsm/kg

Question 22

Ingestion of what can cause osmotic diarrhea?

Answer 22

Ingestion of poorly absorbed ions or sugars or sugar alcohols – Mannitol, sorbitol – Magnesium, sulfate, and phosphate

Question 23

What is the difference in monosachs vs disachs in regards to absorption and causing osmotic diarrhea

Answer 23

Monosaccharides—but not disaccharides— can be absorbed.

– Disaccharide deficiency will prevent absorption.

– Lactase deficiency most common

Question 24

Disappears with fasting Or cessation of the offending substance.

Answer 24

Osmotic diarrhea

Question 25

Electrolyte\_\_\_\_\_\_ is not impaired in osmotic diarrhea and • Electrolyte\_\_\_\_\_\_ in stool water are usually quite low

Answer 25

absorption concentrations

Question 26

Common causes of Secreatory Diarrhea (3)

Answer 26

M Either net s_ecretion of anions_ (chloride or bicarbonate) – Or _inhibition of net sodium absorption_. • The most common cause is infection. (• Peptides produced by endocrine tumors )

Question 27

Enterotoxins are little fuckers that cause secreatory diarrhea how?

Answer 27

– Interact with receptors and modulate intestinal transport – Block specific absorptive pathways, in addition to stimulating secretion. – Inhibit Na+-H+ exchange in both the small intestine and colon

Question 28

Two more common causes of osmotic diarrhea

Answer 28

Mg ingestion Lactase deficency; disachs pull water with

Question 29

Whats the cutoff between acute and chronic diarrhea

Answer 29

* Acute Diarrhea: – Symptoms lasting ≤ 14 days * Persistent Diarrhea: – Symptoms lasting 14 to 28 days * Chronic Diarrhea – Symptoms lasting \> 28 days

Question 30

Causes of Acute Diarrhea

Answer 30

• Infection Responsive for almost all Acute diarrhea • Bacteria • Parasites • Protozoa • Viruses • Food allergies • Food poisoning • Medications • Initial presentation of chronic diarrhea

Question 31

Chronic diarrhea can cause Steatorrhea which can result from:

Answer 31

– Malabsorption syndromes – Mesenteric ischemia – Mucosal diseases (e.g., celiac disease, Whipple's disease) – Short bowel syndrome – Small intestinal bacterial overgrowth – Maldigestion

Question 32

two reasons for maldigestion leading to steatorrhea

Answer 32

Inadequate luminal bile acid concentration • Pancreatic exocrine insufficiency

Question 33

What do we need to look for when getting histroy of diarrhea?

Answer 33

* Assess volume status (symptomatic orthostasis, fluid intake, etc) • Try to assess constancy • Frequency • Abdominal Pain * Tenesmus • Nocturnal waking • Gas/bloating • Blood in stool is never normal (unless known pathology). • Flatuphobia

Question 34

Random questions to look for when getting pt history for diarrhea

Answer 34

• Past medical history • Recent and remote travel • Pets (pet **turtles**) • Hobbies (drinking from **mountain streams**). • Diet: **sorbitol, caffeine, large amount of HFCS, alcohol intake**

Question 35

one more tidbit on diarrhea history taking

Answer 35

• Medication Changes – NSAIDs and Olmesartan causing Sprue like illness. • Family History – Celiac, IBD • PMH: Autoimmune conditions (Celiac and IBD)

Question 36

What should be on our DDx if pt has diarrhea with Fever

Answer 36

* Invasive bacteria * Enteric viruses * Cytotoxic organism – Clostridium difficile or Entamoeba histolytica * Ischemia * IBD

Question 37

Pt has diarrhea within 6 hours of eating: what does this suggest?

Answer 37

Began within six hours – Suggest ingestion of a toxin – Staphylococcus aureus or Bacillus cereus

Question 38

When do you suspect Clostriudium perfringines as causitive agent

Answer 38

diarrhea w/in 8-14 hours of ingetsion of food

Question 39

At more than 14 hours diarrhea result from \_\_\_\_\_, non-specific.

Answer 39

viral or bacterial infection

Question 40

recent antibiotic use or pts on chemotherapy could account for diarrhea dt

Answer 40

C. Diff

Question 41

What should we focus on during our physical exam?

Answer 41

• Initially focused on volume status . • Signs of other systemic disease – DH in Celiac disease – EN or arthritis in IBD * Abdominal tenderness/mass * Rectal exam (fistula, bloody stool)

Question 42

When is the right time to order stool for pathogens?

Answer 42

when pt is VERY ill or has risk factors for infection

Question 43

When are ELISAs or DFA microscopy beneficial or useful

Answer 43

* Useful in setting of proper history or immune compromised * Giardiasis and Cryptosporidium in stool – sensitivities greater than 90% – specificities approaching 100%

Question 44

Osmotic Gap =

Answer 44

Serum Osm – Est stool Osm (290)

Question 45

Almost all of the osmotic activity of stool is accounted for by electrolytes (unlike serum) – Therefore, (2 × ([\_\_]+ [\_\_])) ~ 290 mmol/L.

Answer 45

Na+ K+

Question 46

Small osmotic gap(\<50 mOsm/kg)

Answer 46

suggestive of secreatory diarrhea

Question 47

– The calculated osmotic gap will be high. – Osmotic gap is present (\>100 mOsm/kg),

Answer 47

osmotic diarrhea

Question 48

what accounts for most of the osmotic activity in osmotic diarrhea

Answer 48

unmeasured osmoles

Question 49

When Osmotic gap is Negative this means:

Answer 49

– Poorly absorbed multivalent anion, such as phosphate or sulfate.

Question 50

Stool osmolality tends to rise once the stool has been collected because of

Answer 50

continuing bacterial fermentation in vitro.

Question 51

Large osmotic gap suggests

Answer 51

magnesium ingestion

Question 52

when is the one time stoool osmolatiry be useful

Answer 52

surreptitious laxitive use: munchousens, eating disorders

Question 53

Common causes of chronic diarrhea that should be worked up

Answer 53

– Celiac disease (Caucasians) – Thyroid disease – IBD – IBS

Question 54

When do we do endoscopy on patients with chronic diarrhea

Answer 54

Most appropriately used for persistent and chronic diarrhea or patients with significant lab abnormalities. (NOT pts with self-resolving diarrhea) – Obtaining biopsies of even normal appearing mucosa is essential.

Question 55

uses and benefits of 72 hour stool collection for fecal fat

Answer 55

* Only useful for chronic diarrhea. * Impractical most of the time

Question 56

What is considered abnormal in fecal fat collection?

Answer 56

7-14 g per 24 hours is considered abnormal but not diagnostic • \>14 g considered indicative of fat malabsorption