irritable bowel syndrome

Question 1

treatment of IBS

Answer 1

fiber supplementation

Question 2

WOMEN (2-3x greater than men)
chronic abdominal pain (LLQ most common): cramping, improves/relieved with defecation, +/- nighttime awakenings
constipation OR diarrhea OR alternating- worsen with stress
+/- pass mucus, bowel urgency, bloating, incomplete stool evacuation sensation, upper GI sx: dyspepsia, nausea, GERD
may have periods of normal bowel habits
onset: 10-30 yo
no weight loss, bloody stools, fever, refractory diarrhea
exam: abdominal and pelvic exam normal
family hx negative for colon cancer or IBD

Answer 2

IBS

Question 3

treatment of IBS - constipation

Answer 3

fiber intake (psyllium - DOC): dietary, synthetic, or natural fiber 
lubiprostone (women only): activates intestinal Cl channels, ↑ fluid secretion
SE: nausea

Question 4

hypersensitive to visceral perception and pain
altered microbial flora
GI motility
dysregulation of brain-gut axis (↑ reactivity to stress)
usually psychosocial factors
psychiatric sx predict illness behavior, psych illness WORSENS IBS sx, doesn’t cause IBS
comorbidities: fibromyalgia, low back pain, chronic HA

Answer 4

IBS

Question 5

diagnosis of IBS: rome criteria

Answer 5

recurrent abdominal pain/discomfort for at least 3 days/mo for past 3 mo (symptom onset at least 6 mo prior) associated with 2 or more of:
-improves with defecation
-onset associated with change in frequency of stool
-onset associated with change in form of stool
initial screening tests if no alarm sx: CBC, stool hemoccult test, colonoscopy if >50yo
r/o meds, diet that can mimic IBS

Question 6

alarm GI features: underlying organic etiology (IBD, colon cancer - not IBS)

Answer 6

fever
anemia
involuntary weight loss >10 lbs (IBD)
heamtochezia
melena 
refractory or bloody diarrhea (IBD)
older age
sudden onset symptoms, major change in sx
family hx of colon cancer or IBD
tests: colonoscopy, CBC, ESR (look for IBD if young or cancer if older)

Question 7

treatment of IBS - diarrhea

Answer 7

loperamide: reduce frequency of loose stools, ↓ bowel urgency
alosetron: severe diarrhea sx for at least 6 mo

Question 8

treatment of abdominal pain of IBS

Answer 8

antispasmodics anticholinergic (dicyclomine, hyoscyamine PRN): mild-mod, infrequent pain
low-dose TCA: more persistent pain + severe pain
SSRI: if comorbid anxiety or depression
rifaximin: antibiotic for traveler's diarrhea, helpful if NO constipation sx
probiotics + peppermint oil

Question 9

multifactorial treatment of IBS

Answer 9

modify diet + lifestyle
patient ed
medication often required
if psychological issues: psychotherapy, stress management, treat underlying psych disorder to IMPROVE IBS sx, CBT