Lecture 10: Small Bowel and Colon Disorders Flashcards
1
Q
What is the Bristol Stool Chart and how does Type 1 differ from Type 7?
A
- Type 1 is on the constipated end of the spectrum w/ stool equal to hard lumps, like nuts (hard to pass)
- Type 7 is on the diarrhea end of the spectrum and is watery w/ no solid pieces (entirely liquid)
2
Q
What is the major cause of death associated with diarrhea?
A
Dehydration
3
Q
Diarrhea for >14 days is most commonly due to a (infectious/non-infectious) cause?
A
Likely non-infectious —> think meds!
4
Q
If a workup is indicated for acute diarrhea which serum labs should you get?
A
- CBC
- Electrolytes
- BUN
- Cr
- Blood culture?
5
Q
Most routine (bacterial) stool cultures include which 4 organisms?
A
- Salmonella
- Shigella
- E. coli (ask for shiga-like toxin detection for O157:H7 EHEC)
- Most detect campylobacter (although may need to be requested)
6
Q
Food poisoning from which bacteria is commonly seen after ingestion of potato salad, mayonnaise or cream pastries?
A
S. aureus = Gram (+) cocci
7
Q
Food poisoning by which bacteria is most commonly associated with ingestion of lunch meat and unpasteurized dairy?
A
Listeria monocytogenes** –> **Gram (+) rod
8
Q
What virulence factor does S. aureus contain that leads to the sx’s of food poisoning?
Type of diarrhea?
A
- Preformed enterotoxins
- Watery diarrhea
9
Q
Which bacteria is associated with food poisoning from fried rice?
Type of diarrhea and what is the main symptom?
A
- Bacillus cereus –> Gram (+) rod
- Watery diarrhea
- Vomiting is the main symptom!
10
Q
Which gram-positive spore-forming rod is associated with food poisoning as a result of consuming inadequately cooked beef, ham, poultry, legumes, or gravy?
Type of diarrhea?
A
- Clostridium perfringens
- Watery diarrhea
11
Q
Shigella spp. food poisoning is most commonly associated with what types of food?
A
Potato or egg salad, lettuce, raw vegetables
12
Q
What type of diarrhea and symptoms are associated with Shigella spp. food poisoning?
A
Begins as watery —> intense colitis w/ fever and frequent small volume stools w/ blood and pus
13
Q
Shigella spp. infection will have what finding in the stool of infected pt?
A
Fecal leukocytes (+)
14
Q
What are post-infectious complications of Shigella spp.?
A
- Reactive arthritis
- HUS
15
Q
Complications associated with Salmonella typhimurium?
A
- Reactive arthritis
- Endocarditis
- Septic arthritis
- Osteomyelitis (sickle-cell pts)
16
Q
Vibrio parahemolyticus is associated with food poisoning from the consumption of what?
What kind of diarrhea?
A
- Seafood (i.e., shellfish, oysters, shrimp)
- Watery —> bloody diarrhea
17
Q
Where is Vibrio vulnificus found?
Most often infects people via what 2 routes?
Common symptoms associated with each route?
A
- Warm, shallow, coastal salt water
- Eating raw shellfish (oysters) –> vomiting and diarrhea
- Open wounds in the water –> bullous skin lesions
18
Q
Vibrio vulnificus infections are life threatening in which patients?
A
- Immunocompromised
- Especially cirrhosis and hemochromatosis pts
19
Q
Aeromonas hydrophila is found in which enviornments?
Most often transmitted how?
A
- Fresh water or brackish water (slightly salty)
- Eating fish or shellfish
- Wounded in the water or open wounds in water
20
Q
Which type of diarrhea can be produced by Aeromonas hydrophila?
A
- Cholera-like: watery rice water stools
- Bloody mucoid stools
21
Q
If someone sustains a wound while in fresh water and then has a rapidly progressive wound infection (i.e., necrotizing fasciitis), which bacteria should be susepcted?
A
Aeromonas hydrophila
22
Q
What are positive serum and fecal findings associated with EHEC infection?
A
- Peripheral leukocytes (+) - CBC
- Fecal leukocytes or lactoferrin (+)
- Stool culture = shiga-like toxin
23
Q
Antibiotic therapy for EHEC increases the risk for?
A
HUS
24
Q
Infections by Yersinia enterocolitica poses a higher risk in which patients?
A
- Pts w/ derangement of iron metabolism
- Iron-overload syndromes, cirrhosis, hemochromatosis, aplastic anemia, and thalassemia
25
Infection by which bacteria can mimic appendicitis due to its localization to the terminal ileum?
*Yersinia enterocolitica*
26
*Listeria monocytogenes* can infect anybody, but has a predilection for whom?
- **Pregnant women**
- Extremes of age
- Immunosuppressed
- Those w/ Hemochromatosis
27
How is *C. difficile* diagnosed?
**Stool** culture - **PCR** for toxin (TcdA and TcdB)
28
Which 4 antibiotics are most commonly associated with infection with *C. difficile?*
1) Clindamycin
2) Ampicillin
3) Cephalosporins (3rd gens)
4) Fluoroquinolones
29
Best preventative measure for minimizing transmission and infection of C. difficile in a hospital setting?
Wash hands w/ **soap and water** + **use of disposable gloves**
30
How is Rotavirus detected?
Characteristic finding on electron microscopy?
- Detected by viral culture **PCR**
- **"Wagon-wheel" appearance on electron microscopy**
31
Who is most commonly affected by Adenovirus and what are the most common symptoms?
- Children
- Fever, chills, myalgias, sore throat
- **Watery** diarrhea
- Conjunctivits
- Pharyngitis
32
How is the Dx of *Strongyloides stercoralis* made?
**- Rhabditiform** **larvae** in stool
**- Eosinophils** in stool
33
Which organism is the 2nd most common cause of Esophageal Varices in Africa?
What other complications?
- *Schistosoma mansoni*
- **Bloody** stools, bladder cancer, and liver cysts
34
Which organism can form cysts in the liver or lungs, which characteristically looks like free-flowing "**hydatid sand" on CT?**
*Echinococcus granulosus*
35
Which 2 bacteria are most often responsible for **inflammatory** diarrhea w/ fecal leukocytes and fecal lactoferrin but **not typically bloody stools**?
1. *Listeria monocytogenes*
2. *Clostridium difficile*
36
Anti-motility agents may be used in patients in whom no fever and non-bloody stools exist, but are **not to be used** if infection is due to which 2 organisms?
- ***C. diff***
- **EHEC**
37
Chronic use of what can lead to **melanosis coli,** a benign hyperpigmentation of the colon?
Laxitives
38
The presence of abdominal pain with **chronic diarrhea** (\>4 wks duration) suggests which 2 disorders may be present?
1) IBS
2) IBD
39
Before embarking on an extensive evaluation for the cause of someones chronic diarrhea the most common causes should be considered which include what 3 things?
1) Medications
2) IBS
3) Lactose intolerance
40
Which signs/symptoms and findings are inconsistent with the most common causes of chronic diarrhea (i.e., **red flags**) and warrant further evaluation?
- Presence of **nocturnal diarrhea**
- **Weight loss**
- **Anemia**
- **Positive FOBT**
41
Evaluation of chronic diarrhea showing a fecal elastase \<100 mcg/g may point to what underlying problem?
Pancreatic insufficiency
42
Neuroendocrine tumors may be localized via what imaging modality?
Somatostatin receptor scintigraphy
43
A patient with **chronic**, high-volume watery diarrhea (\>1L/day) with **normal** osmotic gap that **persists during fasting** should raise suspicion of which disorder?
Neuroendocrine tumor
44
Which non-invasive breath tests can be used for the diagnosis of small bowel bacterial overgrowth?
**Glucose** or **lactulose** or **14C-xylose** breath tests
45
Carbohydrate malabsorption is common and should be considered in all patints with chronic, postprandial diarrhea, and can be confirmed by which tests?
- Elimination trial for 2-3 weeks
- **Hyrdrogen breath tests**
46
What are the 2 major subtypes of Microscopic Colitis?
1) Lymphocytic colitis
2) Collagenous colitis
47
What are some of the meds that have been implicated in Microscopic Colitis (i.e., collagenous and lymphocytic colitis)?
- **NSAIDs**
- PPIs
- Low-dose aspirin
- SSRIs
- AChE inhibitors
- Beta-blockers
48
What is the first line treatment for the diarrhea associated w/ Microscopic Colitis?
Antidiarrheal therapy w/ **loperamide**
49
How is stool osmotic gap?
What is a normal value?
- Difference between **measured** osmolality of the stool (or serum) and the **estimated** stool osmolality
- Normally **\<50 mOsm/kg**
50
An osmotic gap \>75 mOsm/kg implies that diarrhea is caused by what?
Ingestion or malabsorption of an **osmotically** active substance
51
A person with diarrhea that has an increased stool osmotic gap and a **stool volume that decreases with fasting** is a clue for what type of diarrhea?
Osmotic
52
In any patients with chronic, postprandial diarrhea what should alway be considered as a cause?
Carbohydrate malabsorption
53
What are some of the most common causes of Osmotic Diarrhea?
- **CHO malabsorption** (lactose, fructose, sorbitol)
- **Laxative abuse = Factitious (could be osmotic or secretory)**
- **Medications**: antacids, lactulose, etc..
54
High-volume watery diarrhea (\>1L/day) with a **normal** osmotic gap is characteristic of what type?
Secretory diarrhea
55
What is the effect of fasting on Secretory Diarrhea?
Little change in stool output
56
What are some common causes of Secretory Diarrhea?
- **Endocrine tumors:** ZE syndrome, Carcinoid syndrome, VIPoma, Medullary thyroid carcinoma
- **Bile salt malabsorption**
57
What is one of the most common causes of chronic watery diarrhea in the elderly?
Microscopic colitis
58
4 characteristic signs/symptoms of Malabsorptive Conditions?
- **Weight loss**
- Osmotic diarrhea
- Steatorhhea
- Nutritional deficiency
59
The steatorrhea associated with Pancreatic Insufficiency is due to malabsorption of?
Triglycerides
60
Characteristic skin rash consisting of pruritic papulovesicles over the extensor surfaces of the extremities and over the trunk, scalp, and neck is a cutaneous manifestation of what malabsorptive disorder?
Celiac disease ---\> **dermatitis herpetiformis**
61
Recommended serological test for Celiac Disease is?
IgA **tTG** antibody
62
Which serologic test has excellent sensitivity and specificity for Celiacs disease and can be useful in pts with IgA deficiency as well as young children?
**IgG anti-deaminated gliadin peptides (DGP)**
63
What is the standard method for confirming the diagnosis of Celiacs in a patient w/ positive serologic tests?
Mucosal biopsy of **prox. duodenum** and **distal duodenum**
64
Why is Dual-energy X-ray densitometry scanning recommended for all patients with sprue?
Screen for **osteoporosis**
65
How is the diagnosis of bacterial overgrowth in the GI confirmed?
**Jejunal aspiration** w/ **quantitative** bacterial cultures
66
Bacterial overgrowth is associated with what type of diarrhea(s)?
**Osmotic** and **secretory** + increased flatulence
67
What are 6 of the most common causes of Short Bowel Syndrome in adults?
1) Chron disease
2) Mesenteric infarction
3) Radiation enteritis
4) Volvulus
5) Tumor resection
6) Trauma
68
Which factors play a role in the type and degree of malabsorption associated with Short Bowel Syndrome?
**-** Depend on the **length** and **site** of the **resection**
**- Degree of adaption** of the remaining bowel
69
Increased erythrocyte sedimentation rate or CRP in a patient with chronic diarrhea suggests which disorder?
IBD
70
What is the most sensitive method for detecting *Giardia* and *E. histolytica* infection?
Fecal **antigen** test
71
What does an adequate normal biopsy of a patient with suspected Celiac Disease mean?
Excludes the diagnosis
72
Most patients with Celiac disease also have what other deficiency?
**Lactose intolerance** either temporarily or permanently and should avoid dairy until intestinal symptoms improve on glute-free diet
73
What is the most common presenting symptom with Whipple Disease?
Others?
- Weight loss = **most common**
- Arthralgias = **first sx's**
- Diarrhea
- Abdominal pain
74
Whipple disease is established (90%) by endoscopic biopsy w/ histo evaluation of which part of the GI?
Duodenum
75
What is the characteristic appearance of Whipple bacillus on electron microscopy?
**Trilamellar** wall
76
Resection of over **50cm** vs. **100cm** of the ileum will lead to what deficiencies and what type of diarrhea associated with each?
What must be done as treatment?
- \>**50cm** = require **monthly subcutanous or IM vit B12** shots; bile salt malabsorption will lead to **watery diarrhea**
- **\>100 cm** = ↓ bile salt pool --\> **steatorrhea** and **ADEK deficiency**. Require a **low-fat diet** and **vitamin supplements**
77
All of the unabsorbed fatty acids as a result of terminal ileal resection will bind to what and lead to what problem(s)?
Should be managed how?
- Bind Ca2+, **decreasing** its absorption and **increasing** absorption of oxalate ---\> **Oxalate kidney stones**
- **Cholesterol gallstones** due to decreased bile salts (**common**)
- **Ca2+ supplements should be given** to bind oxalate and increase serum Ca2+
78
What % of the small intestine can be resected and is usually well tolerated?
40-50%
79
Resection of the colon + 100 cm of proximal jejunum should be managed how?
Main goal?
- **Maintain adequate oral nutrition**
- Low-fat, high-complex CHO diet
80
With a full colon resection + less than 100-200cm of jejunum left, how should this pt be managed nutritionally?
NEED **parenteral nutrition**
81
Duodenal resection will lead to malabsorption of which vitamins?
Folate, iron, or calcium
82
What is the most common cause of chronic diarrhea in young adults + the most common GI disease in clinical practice?
IBS
83
What are the 3 types of clinical presentations for IBS?
1. Spastic colon (chronic abdominal pain and constipation)
2. Alternating constipation and diarrhea
3) Chronic, painless diarrhea
84
Pts presenting with IBS to a physician have an increased frequency of what type of disturbances?
**Psychological** --\> Depression, hysteria, OCD
85
Patients with IBS often report relief of abdominal pain with?
Bowel movements
86
How long must the symptoms associated with IBS be present for a diagnosis and how long for it to be considered a differential?
Chronic \> 6 months (sx's for at least 3 mo. before considering it a differential)
87
When assessing a patient with IBS you need to ask about **"alarm symptoms,"** which include what 6 things?
- **Acute** onset of sx's
- **Nocturnal** diarrhea
- **Severe** constipation or diarrhea
- **Hematochezia**
- **Weight loss**
- **Fever** = incompatible w/ dx of IBS
88
What are the 3 ROME diagnostic criteria for IBS?
1. **Improvement** with defecation
2. Onset associated w/ a change in **frequency** of stool
3. Onset associated w/ a change in **form (appearance)** of stool
\*Criteria filled for **last 3 months** with sx onset at least **6 months** before diagnosis\*
89
In patients w/ IBS that have a lot of diarrhea, bloating, and flatulence which dietary restriction should be considered to improve symptoms (hint: mnemonic)?
- Dietary restriction of "**FODMAPS"**
- **F**ermentable **O**ligosaccharides, **D**isaccharides, **M**onosaccharides, and **P**olyols
90
XR or CT demonstrating colon dilation, confined to the cecum and proximal colon without signs of mechanical obstruction is consistent with what disorder?
Acute colonic pseudo-obstruction (**Ogilvie Syndrome**)
91
A cecal diameter greater than _______ cm is associated with increased risk of colon perforation and requires intervention.
A cecal diameter greater than **10-12 cm** is associated with increased risk of colon perforation and requires intervention.
\***Ogilvie Syndrome**
92
How often should Cecal size be assessed with an abdominal radiograph in a patient with Acute Colonic Pseudo-Obstruction (Ogilvie Syndrome)?
Every **12 hours**
93
What are major differences between **antibiotic-associated diarrhea** and **antibiotic-associated colitis?**
- **ABx- assoc. diarrhea** = most cases **NOT** due to *C. difficile* + Diarrhea typically occurs during period of ABx exposure and **resolves** **spontaneously** w/ discontinuation
- **ABx-assoc. colitis** = **almost always** due to *C. difficile* and sx's can be **mild** to **fulminant**
94
Patients on antibiotics and what other drug in a hospital setting are at a higher risk of acquiring *C. difficile* and developing *C. difficile*-associated diarrhea?
PPIs
95
*C. difficile* should be considered in all hospitalized patients with unexplained?
Leukocytosis
96
Which labratory findings (i.e., WBC's, albumin, and others) are suggestive of severe disease in patient with *C. difficile?*
- **WBC** \>30,000/mcL
- **Albumin** \<2.5 g/dL (protein-losing enteropathy)
- **Elevated** serum **lactate**
- **Rising** creatinine
97
In patients with severe *C. difficile* colitis what will be seen on flexible signoidoscopy?
Characteristic findings.
- True **pseudomembranous** colitis
- Classic **"volcano" exudate** of fibrin and neutrophils
98
Diverticulitis is best staged and confirmed with what imaging modality?
Which imaging modality is contraindicated?
- Best = **CT with contrast**
- Endoscopy is **contraindicated** during initial stages of an acute attack due to **risk of perforation**
99
Pts with weight loss, who have been experiencing a dull, crampy periumbilical pain 15-30 mins after a meal that lasts several hours and often report a "food fear" need to be evaluated for?
Chronic Mesenteric Insufficiency (aka **"abdominal angina**)
100
What is the American Cancer Society guidelines for colorectal cancer screening for all people at average risk?
- Start regular screening at **age 45**
- Continue screening through **age 75** (screening after 75 is based on personal preferences, life expectancy, overall health, and prior screening hx)
101
What is the recommeded screening for CRC in a patient w/ a first-degree relative w/ CRC or adenomas diagnosed \<60 yo or two first-degree relatives of any age?
Colonoscopy every 5 years, **beginning at age 40** or **_10 years before the age_** of the youngest affected relative (whichever is first)
102
When should screening for CRC begin in someone with FAP?
**10-12 yo**
103
When should screening for CRC begin in someone with HNPCC?
Beginning at **age 20-25 yo** and every **1-2 years** or **10 years younger** than youngest age of CRC diagnosis in family
104
What is a more sensitive test for CRC and advanced adenomas compared to FOBT?
**FIT** = fecal immunohistochemical test for hemoglobin
105
What are ways that colonic polyps can be identified and treated?
Which are recommended and which are not?
- Barium enema (not recommended) or CT colonography (okay, but only for low risk pt)
- **Colonoscopy** = best choice --\> **diagnostic** and **therapeutic** (polyectomy)
106
What is the recommended treatment for FAP?
**Prophylactic** colectomy to prevent otherwise **inevitable** colon cancer
107
Lynch syndrome (aka HNPCC) is due to mutations in genes essential in?
DNA base-pair mismatches: *MLH1, MSH2*
108
The diagnosis of Lynch Syndrome (HNPCC) is suspected with what type of test/finding?
Diagnosis is confirmed via?
- Diagnosis **suspected** by tumor tissue **immunohistochemical staining** for **mismatch** repair proteins or testing **microsatellite instability**
- **Confirmed** by genetic testing!
109
For woman with Lynch syndrome (HNPCC) at age 40 or once they have finished childbearing, what is the recommended treatment?
**Prophylactic hysterectomy** and **oophorectomy**
