Irritable bowel syndrome Flashcards
1
Q
Definition of IBS
A
- Collection of symptoms including chronic ab pain and irregular bowel movements in the absence of structural abnormalities
- Can be accompanied by constipation, diarrhea, or both (mixed)
- Associated w/ fibromyalgia, interstitial cystitis
2
Q
Pathophysiology of IBS
A
- Etiology is stress, both psychological (depression, anxiety, sexual abuse as child) and physical (activity limitations, enterocolitis)
- Hallmark of IBS pathogenesis is visceral hypersensitivity
- Visceral hypersensitivity: increased sensitivity to distention of lumen, associated w/ bloating/pain during eating
- No role of SI bacterial overgrowth, but there are intestinal spasms/cramps (due to CNS stress) and reduced ability to move gas
- CNS stress leads to intestinal spasms, non-absorbed food fermented by bacteria forming gas pockets
- Lower motility of gas pockets and visceral hypersensitivity lead to bloating and pain
3
Q
Dx of IBS
A
- Rome criteria: recurrent abd pain for at least 3 mo w/ 2 of the following
- Relief w/ defecation, change in stool consistency, change in stool frequency
- Must rule out red flags: if red flags are present indicates there is pathology other than IBS
- Severe (excruciating) abdominal pain, heavy diarrhea, weight loss, rectal bleeding, fever, abd or rectal mass
- Red flag labs: Fe def anemia, low albumin, high ESR/CRP, WBCs in stool, high stool calprotectin (indicates IBD)
4
Q
Rx of IBS
A
- Decrease fat in diet, decrease roughage (complex CHO) in diet since they are not absorbed and get fermented into gas
- Increase exercise, psychotherapy (CBT), may add psyllium to diet
- Drugs: anticholinergic (anti-spasmodics: phenobarbital), antidepressants (tricyclics and SSRIs), 5HT agonists (tegasorod, for constipation predominant IBS) and antagonists (alosetron only for diarrhea predominant IBS in women), antibios, probiotics
- Most important: support and empathy
