What are the sx of IBS?
- abdominal pain/discomfort
- altered bowel habits
- physical and emotional distress
What are the proposed mechanisms of IBS?
- Alterations in GI motility
- Visceral perception
- Response to intraluminal contents
- Mucosa-flora interactions
- Neuroimmune modulation of gut functions
- Psychosocial stressors may exacerbate severity of IBS sx
What medications are commonly used to relieve IBS abdominal pain?
- Myorelaxants - none effective in U.S.
- Opioid agonists - not proven
- Peppermint oil - not definitive
What medications are used for IBS gas, but don't work?
- α-galactosidase (Beano)
- Activated charcoal
What antibiotics may be beneficial for IBS bloating?
What is the MOA of antibiotics in IBS bloating?
decreased bacterial overgrowth to decrease volume and production of gas production
What is the MOA of fiber in C-IBS?
improve stool consistency and decrease colonic transit time
What is the recommended dose of fiber for C-IBS?
What traditional tx for constipation have no use in C-IBS?
- stool softeners (docusate)
- emollients (mineral oil)
- stimulants (bisacodyl, cascara, senna phenolphthalein, ricinoleic acid)
- osmotic lasatives (glycerin, lactulose, Mg, sodium phosphate, sorbitol)
What traditional tx for constipation may have some benefit in C-IBS?
What is the MOA of lubipristone in C-IBS?
activation of CLC2 chloride channels, increasing intestinal secretions to increase motility
What type of IBS is lubipristone approved for?
C-IBS in women > 18yo
What is the MOA of loperimide in D-IBS?
- decrease intestinal transit (watch high doses - could cause constipation)
- increase intestinal and ion absorption
- increase anal tone at rest
- increase consistency
- decrease frequency
- no effect on pain
Wht is the MOA of alosetron (Lotronex) in D-IBS?
- slows colonic transit time
- increases fluid absorption
- increases consistency
- decreases pain
What type of IBS is alosetron approved for?
Women w/ severe D-IBS refractory to conventional tx