CM: Bowel Mvt Changes

Question 1

In a FDR w/ colon cancer, what factor can help assess risk?

Answer 1

FDR’s age at dx, if >60 y/o, more likely sporadic than genetic; would not portend higher risk for patient

Question 2

With recent change in bowl habits, what would be the next step to diagnose cause of diarrhea?

Answer 2

Colonoscopy

Question 3

What would argue vs. a trial Tx for possible Irritable Bowel Syndrome?

Answer 3

Red flags such as weight loss, nocturnal bowel movements, etc- these would point to a more pathologic process rather than functional

Question 4

Assess the status of this colon on colonscopy

Answer 4

Normal w/ pale mucosa, uniformity in appearance and normal vasculature

Question 5

With a normal appearing colonscopy, what would be the next step to assess patient’s diarrhea?

Answer 5

Random biopsies of normal appearing colon

Question 6

Despite colon’s normal appearance on colonoscopy, what might a biopsy like this one reveal?

Answer 6

Lymphocytic Colitis, a type of microscopic colitis

Question 7

Aside from Lymphocytic Colitis, what is another type of microscopic colitis?

Answer 7

Collagenous Colitis

Question 8

What histologic features do Lymphocytic Colitis and Collagenous Colitis share? What is their distinction?

Answer 8

Share incr intraepithelial lymphocytes

Thickened collagen band > 10 microns

Question 9

Account for the EPI of Microscopic Colitis and list some clues for its diagnosis

Answer 9

EPI: 10-20% of chronic watery diarrhea

Clues:
F>M
>50 y/o
Nocturnal sx
New or recent changes in medications
Autoimmune diseases (ex: hypothyroidism may lead to 2nd autoimmune process)

Question 10

What is the first step in management of Lymphocytic Colitis if patient takes NSAID for arthritis? What is a possible complication that can arise? What are some medication alternatives?

Answer 10

Discontinue ibuprofen, add budesonide (80% effective)
9 mg/day for 6-8 weeks; taper 6 mg/d (1-2 weeks), 3 mg/d (1-2 weeks), then stop

60-80% relapse w/ cessation

Alts: Prednisone (Budesonide spares AE’s)
Bismuth
Mesalamine

Question 11

If patient is counseled to stop smoking bc this poses an incr risk of microscopic colitis, what other medication apart from NSAIDs poses a risk?

*Special Consideration*

Answer 11

Omeprazole

PPI’s ↑likelihood of microscopic colitis
Synergy: Omeprazole + NSAID ↑ risk than either alone

Question 12

What are the 3 main associations w/ Microscopic Colitis?

Answer 12

1) Smoking: ↑ risk & onset by 10 years early
2) Celiac Disease: 5%, 70x greater risk

3) Medications:
NSAIDs
PPI
SSRI
Anti-Parkinson Meds
*Usually short exposure time*

Question 13

What type of bowel change calls for an infectious stool study?

Answer 13

Infection would present as diarrhea, not as constipation

Question 14

What is the best diagnostic test?
What are your suspicions?

60 y/o f px w/ new onset constipation over past 3 days. She notes worsened LLQ pain but w/o F/C. No change in medication. PE reveals focal LLQ tenderness w/ guarding, no rebound. Elevated WBC’s

Answer 14

Abdominal CT scan bc suspicion of diverticulosis from change in bowel habit, leukocytosis & LLQ pain

Question 15

What does this abdominal CT scan reveal?

Answer 15

Acute Uncomplicated Diverticulosis

Wall thickening, hyperemic bc brighter- w/ fat stranding
↑ density of soft tisue & pericolic fat

Question 16

If acute diverticulosis becomes complicated, what are 3 possible findings?

Answer 16

Abscess, Fistula, Perforation into abdomen

Question 17

With dx of acute diverticulitis, broad spectrum antibiotics are initiated w/ what other step in management? Why?

Answer 17

Colonscopy 6-8 weeks after recovery and antibiotic completion to rule out underlying carcinoma

*CI: immediate colonscopy bc risk of perforation

Question 18

Describe the management of Acute Diverticulosis

Answer 18

NPO initially but bowel rest, later can advance w/ low residue diet (low fiber, fewer leafy greens & fruits bc indigestible and can tax GI)
*No data to support eliminating nuts and seeds*

Question 19

Is surgery indicated after the first episode of Acute Diverticulitis?

Answer 19

No bc 20% will have recurrence, although segmental resection can reduce frequency of recurrence

Question 20

How is Complicated Diverticulosis managed? How does it compare w/ uncomplicated disease?

Answer 20

Non-surgical Tx for uncomplicated disease

Complicated Disease (15% of cases)

• Abscess < 4cm: ab’s and low residue diet
• Abscess > 4cm: IR drainage & eventual elective surgery
• Urgent surgery: peritonitis, perforation, medical therapy failure, undrainable abscess, obstruction

Question 21

Describe the EPI of Recurrent Diverticulitis

Answer 21

Recurrent attacks: 15%
Higher recurrence in the young (<40 y/o)
Recurrent episodes not necessarily more serious
Even after elective resection, recurrence: 10%

Question 22

When would a diverting colostomy be performed w/ a Hartmann’s pouch? Describe the procedure

Answer 22

Recurrent diverticulosis w/ inflamed abdomen in earlier spot, complicated by perforation. PE may exhibit diffuse abdominal tenderness w/ rebound

Hartmann:

1) Remove colon section w/ active inflammation and infection, though 2 ends not anastomosed
2) Make a blind pouch w/ colostomy bag
3) Reconnect 2 ends and eliminate ostomy AFTER infection passes

Question 23

How should surgeon proceed if, prior to reanastomosis surgery, colonscopy (to exclude cancer) shows rectum inflamed w/ ulcers?

Answer 23

Continue as planned w/ re-anastomosis-resolves inflammation so no need to delay!

Tx for Diversion Colitis
Stasis changes bacterial flora, deficiency in short chain FA’s, occurs within 3 mo’s
Sx: bleeding, discharge, pain (or asx)

Question 24

What is the pathophysiology of Diversion Colitis?

Answer 24

Deficiency of short chain FA’s due to diversion of fecal stream, normally absorbed by simple diffusion and ion exchange
Fewer anaerobic flora- lack of CHO and protein metabolites

Question 25

65 y/o male patient px w/ pain followed by acute onset of diarrhea, known to be on dialysis from end-stage kidney disease, w/ vasculopathy and CAD. PE: LLQ tenderness. What is the best test to evaluate and what might you find?

Answer 25

Abdominal CT Scan **Isolated Left Sided Colitis** Wall thickening

Question 26

If **isolated left sided colitis** is suspected after abdominal CT, what is the next best step in management? What might this reveal?

Answer 26

``` Colonscopy to confirm dx (Pain may have occured before stool change bc of inflammation) Only in this case, **ischemic colitis**! Note ulcer (resembles plaque) & hemorrhage in C) ```

Question 27

Where does **Ischemic Colitis** usually occur? Why? How would **Infectious Colitis** compare?

Answer 27

Usually in watershed areas, overlap of where 2 blood supplies meet Ex: Ischemia prone for far reaching areas w/ fewer collaterals Infectious Colitis would have a more uniform pattern

Question 28

How does **Ischemic Colitis** present and what are its risk factors?

Answer 28

Abdominal pain and bloody diarrhea RF's: Elderly, F\>M Comorbidites: Vascular Disease, COPD, HTN, AFib, Constipation Less common in youth so consider: hypercoagulable conditions, collagen vascular disease, long-distance runners, smokers, drug users (cocaine, amphetamines) that vasoconstrict, OCP's, birth control

Question 29

65 y/o male patient px w/ pain followed by acute onset of diarrhea, known to be on dialysis from end-stage kidney disease, w/ vasculopathy and CAD. PE: LLQ tenderness. If CT shows isolated r sided colitis, what is the next best step in management?

Answer 29

CT Angiography SMA supplies R side of colon but also small bowel. Need to ensure small bowel is not ischemic bc there are not many collaterals from SMA unlike in other watershed areas. Possible "**mesenteric ischemia**"=medical emergency

Question 30

With a normal EGD and colonoscopy in a 75 y/o f who reports abdominal pain, diarrhea and weight loss over six months w/ incr bloating and flatus but w/ good appetite- what might be the next step in evaluation?

Answer 30

Glucose H Breath Test Look for bacterial overgrowth as alerted by diarrhea, bloating, flatus

Question 31

**Small Intestine Bacterial Overgrowth (SIBO)** Describe the characteristics and sx Method of Diagnosis Biopsy findings

Answer 31

↑ concentration of aerobic & anaerobic bacteria in small intestine; sx: gas, bloating, diarrhea, steatorrhea, malabsorption w/ fats, CHO's, macrocytic anemia Dx: Glucose H Breath Test (40-80% SN) Lactulose Breath Test (more frequent false +'s) Small bowel biopsy may be normal or w/ non-SP changes; mucosa isn't the issue but inhabitants Lymphocytosis is non-SP

Question 32

Describe the pathophysiology of SIBO

Answer 32

2 risk groups: narrowing-\> stasis

Question 33

What is your next step in management after you diagnose your patient w/ **SIBO** on breath test?

Answer 33

**Rifaxamin**: ab Not absorbed systemically Works on GI flora w/ few AE's, well tolerated Similar ab in hepatic encephalopathy, ↑ ammonia in liver

Question 34

What is your next step in evaluation of this patient's intermittent diarrhea?

Answer 34

No further testing needed

Question 35

How is **Irritable Bowel Syndrome (IBS)** diagnosed?

Answer 35

Rome IV Criteria: (good enough)-attached Re associated w/ change in stool frequency-improves w/ bowel movement/intermittent diarrhea Absence of red flags: blood, nocturnal sx, weight loss, unexplained anemia, abnormal thyroid

Question 36

What is this condition's epidemiological association?

Answer 36

More likely to occur in anxious females

Question 37

**Post-Infectious IBS** Describe the EPI Risk Factors Weight of causative agent

Answer 37

25% of individuals w/ acute diarrhea RF's: female anxiety/depression ↑ duration of illness ab use Causative infectious agent unimportant

Question 38

What is the relationship between Irritable Bowel Syndrome and bloating?

Answer 38

Unlikely to have an ↑ in either small or large bowel gas volume \*Handling of normal amount of air has changed\* Visceral hypersensitivity shown w/ gas infusion or balloon distension do NOT have excess gas volume and do NOT have ↑ incidence of SIBO

Question 39

Which Tx has the greatest benefit for IBS?

Answer 39

Good physician patient relationship (\>30%) \*\>50% higher response in decreasing symptom severity re trust and regularity Rifaxmin (9-10%) Linaclotide (8%)

Question 40

What are the diarrheal and constipation medications used in IBS?

Answer 40

Question 41

What is the recommended diet in IBS tx? What are the effects?

Answer 41

Low FODMAP diet Similar results to Rifaxamin but at lower cost Probiotics w/ some efficacy but no strong evidence to support specific strains

Question 42

What are FOMDAP's?

Answer 42

Short chain fermentable carbs - Poorly absorbed - Osmotically active - Rapidly fermented by colonic bacteria

Question 43

What is the most common cause of death from GI infections in the US? What is 2nd? What is the most deadly but much less common?

Answer 43

1st: **C Diff** 2nd: **Norovirus Listeria:** most virulent but much less common

Question 44

What is something to remember regarding hygienic prevention of small intestine viruses?

Answer 44

Hand washing alone won't control epidemic

Question 45

**Viral Gastroenteritis** Type EPI Transfer Mechanism of diarrhea Tx

Answer 45

Enteral type EPI: 75% of acute diarrhea No lifelong immunity Transfer: fecal oral, aerosolized vomit, fomites Diarrheal Mech: Villous shortening-\>SA loss Loss of disaccharides on cell surface (lactase loss) may even have transient lactose intolerance Tx: Supportive

Question 46

**ETEC-Traveler's Diarrhea** Transfer Sx onset Tx Prophylaxis: when?

Answer 46

Food/H2O/Fecal/Oral Sx within 1-3 days of exposure Tx: mild-**Rifaximin** severe-**Ciprofloxacin/Azithromycin** dysentery-**Azithromycin** Prophylaxis: **Bismuth Subsalicylate** esp w/ gastric bypass

Question 47

Student goes to a conference. After a fancy meal, develops watery diarrhea and bloating 7 days later. After 1 week of persistent sx, goes for evaluation. What is the most likely organism?

Answer 47

**Cyclospora:** parasite \*clue: duration-bacterial infectious diarrhea outside of a week will be chronic

Question 48

**Cyclospora**: Small Intestine Protozoa Characteristic Sx Duration Dx Toxin Type

Answer 48

Usually non-invasive Last too long to be viral Dx: stool tests for ova and parasite; 3 separate specimens Preformed toxins cause sx earlier

Question 49

Give examples of *non-invasive* viruses, parasites, and bacteria in the small intestine

Answer 49

Non-invasive Viruses: Rotavirus, Norovirus, Adenovirus, Astrovirus Parasites: Giardia lamblia, Cryptosporidium, Cystoisospora belli, Cyclospora Bacteria: ETEC, EAEC, Vibrio Cholera, Listeria (also colon)

Question 50

What is the most common *invasive* ileocolonic bacterial infection in US? Give Source Sx Tx (if early), concern re resistance Associated Syndrome

Answer 50

**Campylobacter** Raw Chicken Sx: N/V, bloody diarrhea Tx: erythromycin, Cipro (if early) \*↑ resistance to Cipro\* **Guillain-Barre Syndrome**: descending paralysis, respiratory distress if reaches chest

Question 51

What 3 pathogenic states can Salmonella induce?

Answer 51

1) Gastroenteritis 75% 2) Bacteremia 10% 3) Typhoid 8%

Question 52

HUS is a complication of ab therapy in which type of infectious diarrhea? How does it present?

Answer 52

**Enterohemorragic E Coli (EHEC) HUS** complication: easy bruising, bleeding, fever, bloody diarrhea

Question 53

Give examples of bacteria, parasites and viruses that can induce ileocolonic invasive infections

Answer 53

Bacteria: Campylobacter, Salmonella (SI also), Shigella, E Coli (O157:H7), C Diff, Yersinia, Aeromonas, Plesimonas, Noncholera Vibrio, Chlamydia LGV, Listeria (SI also) Parasites: Entamoeba histolytica, Trichuris (whipworm), Schistosomiasis Virus: CMV

Question 54

How do you Tx infectious diarrhea?

Answer 54

Abx not used routinely bc self-limiting 75% of cases viral, anyway Use ab's if -Severe disease: bleeding & pain -Suggest invasive infection (bleeding) +'s of ab's outweight low risk potential complications from treating EHEC can withhold Tx while awaiting stool tests