IBS

Question 1

Irritable Bowel Syndrome

Answer 1

-GI syndrome characterized by chronic abdominal pain and altered bowel habits in the absence of any known organic cause

Question 2

Epidemiology of IBS

Answer 2

• most prevalent GI disease
• Female: Male 2:1
• most patients develop symptoms at <1% of IBS patients have refractory disease
• usually associated with psychosocial distress
• become chronic healthcare users

Question 3

Pathophysiology of IBS

Answer 3

• uncertain etiology
• motility disorder
• visceral hypersensitivity
• intestinal inflammation
• intestinal microbial changes
• psychological

Question 4

Motility Disorder

Answer 4

• colonic motility is considered the main culprit
• no particular motility pattern has been identified
• treatment is aimed at altering the underlying dominant motility pattern
• mostly constipation

Question 5

Visceral Hypersensitivity

Answer 5

• increased sensitivity to pressure and pain stimulus
• Distention
• Bloating: half of patients have this complaint results from slow transit

Question 6

Intestinal Inflammation

Answer 6

certain patients show increased inflammatory markers (TNF and other cytokines)

Question 7

Microbial Alterations

Answer 7

• Post infectious IBS
• Alterations in Gut microbes
• Bacterial Overgrowth

Question 8

Psychological Causes

Answer 8

• IBS patients tend to have more psychological diagnoses
• various studies have shown abuse as an independent risk factor for IBS
• corticotropin releasing factor (CRF) as possible mediating factor

Question 9

Rome III Diagnostic Criteria IBS

Answer 9

• recurrent abdominal pain or discomfort for 3 consecutive days a month in last 3 months associated with 2 or more:
  1. improvement with defecation
  2. onset associated with a change in frequency of stool
  3. onset associated with a change in form (appearance) of stool

Question 10

Manning Criteria for IBS

Answer 10

• likelihood of IBS increases with number of criteria present
  1. pain relieved with defecation
  2. more frequent stools at onset of pain
  3. looser stool at the onset of pain
  4. visible abdominal distention
  5. passage of mucus
  6. sensation of incomplete evacuation

Question 11

IBS Subtypes

Answer 11

IBS-C: hard stool >25% of stool
IBS-D: loose/watery stool>25% of stool
Mixed IBS: loose and hard stool alternate>25% each
Unsubtyped

Question 12

Diarrhea in IBS

Answer 12

> 3 stools/day
frequent non-bloody stools of small volume
usually AM or post-prandial
does not awaken patient
may be associated with urgency or feeling of incomplete evacuation

Question 13

Constipation in IBS

Answer 13

<3 stools/week
may be constant or intermittent
stools may be hard or pellet-shaped

Question 14

Alternating Constipation/Diarrhea

Answer 14

-most frequent type of altered bowel habits seen in IBS

Question 15

Red Flags in Diagnosis of IBS

Answer 15

• signs/symptoms suggest organic disease is present and symptoms are not IBS
• history-weight loss, severe chronic diarrhea or constipation, rectal bleeding, onset of sx in patient >50, recent travel or abx use, family history of GI cancer, sprue, IBD

Question 16

Red Flags in Physical Exam/Lab Diagnosis of IBS

Answer 16

• arthritis, lymphadenopathy, abdominal mass

- anemia, abnormal thyroid test, abnormal Ca, abnormal liver tests, leukocytosis

Question 17

Evaluation of IBS

Answer 17

• good H&P
• CBC, stool for hemoccult
• clinical diagnosis, therapeutic trial
• further work-up if indicated or symptoms persist

Question 18

IBS Symptoms: Pain

Answer 18

• abdominal X-ray
• CT scan
• ultrasound
• small bowel X-ray

Question 19

IBS Symptoms: Constipation

Answer 19

• TSH, Ca

- Colonoscopy if >50

Question 20

IBS Symptoms: Diarrhea

Answer 20

• Hx of lactose intolerance
• stool studies with recent travel or abx use
• stool for fat
• serology for sprue
• sigmoidoscopy with biopsies

Question 21

Treatment of IBS

Answer 21

• based on nature/severity of symptoms & whether psychosocial impairment is also present
• therapeutic relationship is important
• Education, Reassurance, Dietary Modification, Drug (abdominal pain, constipation, diarrhea)
• psychological treatment

Question 22

Dietary Treatment of IBS

Answer 22

• certain foods may cause symptoms in some individuals-fatty foods, alcohol, caffeine, beans
• Food dairy- may help determine exacerbating foods

Question 23

Drug Treatment of IBS

Answer 23

• fiber: may help with constipation
• Loperamide: symtomatic control of diarrhea
• Anti-cholinergics: pain & bloating
• will control in most patients

Question 24

Treatment for IBS with more severe symptoms

Answer 24

• anti-depressants: used for more severe pain, psychotrophic effect, modulated GI motility, may modulate visceral hyperesthesia
• tricyclic antidepressants (amitriptyline, imipramine, nortriptyline, desipramine) used at doses lower than for depression
• SSRI (especially with psychiatric disorders), give for 3-4 weeks

Question 25

Other Therapies for IBS

Answer 25

• Lubiprostone: locally acting chloride channel activator that enhances chloride-rich intestinal fluid secretion used in constipation predominant IBS
• Abx
• Guanylate Cyclase -2c (GCS-2C)
• Laniclotide (Linzess)
• Plecanatide

Question 26

Psychological Treatment in IBS

Answer 26

• useful for severe symptoms, especially associated with psychiatric disorders or past history of abuse
• cognitive-behavioral treatment, stress management, and behavioral modification may all be useful