27 Inflammatory Bowel Syndrome Flashcards
1
Q
Irritable bowel syndrome (IBS)
- frequency
- ?
- presentations and etiologies
- response to medical therapy
- epidemiology
A
- most common gastrointestinal diagnosis in American and Western Europe.
- functional bowel disease,
- there is an abnormality of function (motility or pain sensitivity), but not a clear anatomic or physiologic problem.
- collection of conditions which respond to a variety of therapies
- many different presentations and probably several etiologies;
- feeble response to medical therapy may result from a failure to address the underlying pathophysiology, including a significant psychological component.
-
Epidemiology
- most common reason for gastroenterology office visits in the US
- Women are twice as likely as men to have IBS.
- similar across ethnic groups.
- first presentation tends to be under the age of 50 years
2
Q
Making a Diagnosis
- characterized by
- IBS symptoms fall into four general categories which may have different pathophysiology:
A
-
characterized by
- abdominal pain and a change in stool habits.
- no typical abnormal findings on histology, imaging, endoscopy, or blood work.
- diagnosis of exclusion,
- all routine testing is normal.
- The diagnosis is clinical and based upon a collection of symptoms.
- Individual symptoms, such as abdominal pain and loose stools are not specific for IBS.
-
IBS symptoms fall into four general categories which may have different pathophysiology:
- Diarrhea predominant (D-IBS)
- Constipation predominant (C-IBS)
- Alternating diarrhea-constipation (A-IBS)
- Normal bowel movements
3
Q
Diagnostic Criteria for IBS:
Manning and ROME Criteria
- There are several different diagnostic criteria for IBS
- Manning Criteria
- ROME Criteria
A
-
There are several different diagnostic criteria for IBS
- The Manning criteria can be, but rarely are used, in clinical practice
- The Rome criteria are mostly used to maintain a standard definition of IBS for clinical trials
- In clinical practice, there are many patients that do not meet these criteria, but still have IBS or something similar
-
Manning Criteria: The more criteria that are met reflect a more accurate diagnosis of IBS (standard threshold of 3):
- Pain relieved by defecation
- More frequent stools with the onset of pain
- Looser stools with the onset of pain
- Visible abdominal distention
- Sense of Incomplete evacuation
-
ROME Criteria: Recurrent abdominal pain (or discomfort) at least three days per month for three months associated with at least two of the following:
- Improvement with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form of stool
4
Q
Diagnostic Criteria for IBS:
Clinical and Historical Characteristics (p.18)
- The diagnosis of IBS is primarily/
- common clinical characteristics:
- historical characteristics that are helpful in the diagnosis of IBS:
A
- The diagnosis of IBS is primarily a clinical diagnosis based upon the typical presentation of symptoms and signs.
-
common clinical characteristics:
- Abdominal pain in any location, but more often below the umbilicus.
- Bloating which is often worse after meals
- Improvement in bloating and abdominal pain after a bowel movement
- Symptoms exacerbated by stress
- Other GI symptoms: dyspepsia (stomach upset), heartburn, early satiety
- Non-GI symptoms: Urinary and sexual difficulty, fibromyalgia
- Diarrhea>>constipation>>alternating diarrhea and constipation or neither
- Depression or anxiety
- History of sexual, physical, or emotional abuse
-
historical characteristics that are helpful in the diagnosis of IBS:
- Abdominal pain/bloating relieved by defecation
- Abdominal pain associated with change in stool consistency
- Psychological distress (anxiety and depression)
- History of physical, sexual, or emotional abuse
- Symptoms beginning after a diarrheal illness
- Affects young men and women
5
Q
Diagnostic Criteria for IBS
- The physical exam
- It is important to consider or exclude certain common diseases which may have symptoms similar to D-IBS. These include:
A
- The physical exam is rarely remarkable for any abnormality except for diffuse abdominal tenderness.
-
It is important to consider or exclude certain common diseases which may have symptoms similar to D-IBS. These include:
- Colon cancer
- Inflammatory bowel disease
- Microscopic colitis
- Celiac disease
- Lactose intolerance
- Tropical sprue
- Small bowel bacterial overgrowth
- Bile salt malabsorption
- Hyperthyroidism
6
Q
Diagnostic Criteria for IBS:
Initial evaluations to consider
- D-IBS
- C-IBS
- If the patient does not respond to one or more IBS therapies/
- Pathophysiology
A
-
D-IBS
- Blood count and electrolytes
- Stool for ova & parasites (Giardia)
- 24 hour stool collection
- Celiac testing
- Breath testing (small bowel bacterial overgrowth/Fructose intolerance)
- Colonoscopy with biopsies (microscopic colitis/inflammatory bowel disease)
- Lactose challenge (lactose intolerance)
- Thyroid levels (hyperthyroidism)
-
C-IBS
- Blood count and electrolytes
- Calcium
- Thyroid levels (hypothyroidism)
- If the patient does not respond to one or more IBS therapies then further studies depending on diarrhea or constipation predominance should be considered.
- Pathophysiology: IBS is most likely a combination of causes which leads to disease
7
Q
Pathophysiology:
Small intestinal bacterial overgrowth (SIBO)
- symptoms
- how many IBS patients have SIBO
- effective in the treatment of SIBO and (to a lesser degree) IBS
A
- The symptoms of SIBO are similar to the symptoms of IBS
- up to two-thirds of IBS patients have SIBO based on a hydrogen breath test.
- Antibiotics, such as ciprofloxacin, metronidazole, neomycin, and rifaximin, have all been effective in the treatment of SIBO and (to a lesser degree) IBS.
8
Q
Pathophysiology: Visceral hypersensitivity (p.22)
- Approximately two-thirds of IBS patients have/
- They experience/
A
- Approximately two-thirds of IBS patients have enhanced pain sensitivity to experimental gut stimulation.
- They experience greater radiation of pain to stimuli and increased peripheral or central sensitization.
9
Q
Pathophysiology:
Inflammation
- 10-25% of IBS patients report that their symptoms began/
- There are increased levels of/
- patients with severe IBS had/
A
- 10-25% of IBS patients report that their symptoms began after a diarrheal illness.
- There are increased levels of pro-inflammatory cytokines including tumor necrosis factor-α (TNF- α) and interleukin-6 (IL-6).
- patients with severe IBS had increased lymphocyte infiltration of the myenteric plexus.
10
Q
Pathophysiology:
Dysmotility:
Findings which may explain some of the IBS symptoms
- Gastric
- Small Intestine
- Colon
- Rectum
A
-
Gastric
- Delayed gastric emptying
-
Small Intestine
- D-IBS – Increased motility
- Poor intestine-intestinal inhibitory reflex
-
Colon
- D-IBS - Increased colonic motility
- C-IBS - Decrease colonic motility
-
Rectum
- Lower rectal compliance and/or higher rectal tension
11
Q
Pathophysiology:
Post-infectious (p.26)
- In approximately 25% of patients, IBS symptoms commence/
- Possible causes of post-infectious IBS include:
A
- In approximately 25% of patients, IBS symptoms commence after a diarrheal illness.
-
Possible causes of post-infectious IBS include:
- Organism invasion and damage of the mucosal nerves.
- An increase in enteroendocrine cells, T lymphocytes and gut permeability.
- Increased healthcare seeking behavior in patients with pre-existing IBS who suffer a diarrheal illness.
12
Q
Pathophysiology:
Psychologic dysfunction
- strong psychological component to IBS.
- A possible explanation for the neuropsychological component of IBS
A
-
strong psychological component to IBS.
- Psychologic and psychiatric disease is common in patients who seek medical care for IBS.
- Depression, anxiety, phobias, and somatization are common.
- perhaps it is the psychologic dysfunction which affects how experience IBS, but does not cause the symptoms.
- Patients with IBS are more likely than controls to have suffered physical, sexual, or emotional abuse.
-
A possible explanation for the neuropsychological component of IBS is that corticotropin releasing factor (CRF), a mediator in the stress response, causes anxiety and depression.
- Administration of CRF increases abdominal pain and colonic motility more so in patients with IBS than controls.
13
Q
Pathophysiology:
Non-celiac gluten sensitivity (NCGS)
- NCGS has emerged as an explanation for/
- patients who reported improved symptoms on a gluten free diet at baseline that were reintroduced gluten or placebo demonstrated/
A
- NCGS has emerged as an explanation for the symptoms experienced by patients who test negative for celiac serologies with normal duodenal biopsies, but have an apparent exacerbation with gluten intake.
- patients who reported improved symptoms on a gluten free diet at baseline that were reintroduced gluten or placebo demonstrated a symptomatic benefit of the gluten free diet.
14
Q
Pathophysiology:
Fructose (FODMAP) intolerance
- acronym
- ?
- include/
- contained in/
A
- Fermentable, Oligo-, Di-, Mono-saccharides And Polyols (FODMAPs)
- short chain carbohydrates which are poorly absorbed in the small intestine and fermented in the colon causing distention and GI symptoms in certain people.
- include fructose (fructans), galactose (galactans), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols) such as sorbitol and mannitol.
- contained in many fruits, vegetables and legumes.
15
Q
Treatment
- There are three components to successful treatment of IBS.
- importance of the therapeutic relationship
- Patient education is particularly important in IBS.
A
-
There are three components to successful treatment of IBS.
- Therapeutic Relationship
- Patient Education
- Medical Therapy
-
importance of the therapeutic relationship
- significant psychological component to IBS.
- Patients have often seen many physicians and have been dismissed as “crazy”, told “it is all in your head” or treated dismissively.
- Many patients have anxiety, depression, and poorly managed stress, which contributes to their symptoms.
- A reassuring relationship with the physician can have a significant effect on patient quality of life and response to therapy.
-
Patient education is particularly important in IBS.
- a patient’s understanding of the physician’s approach instills confidence in the patient.
- reassure the patient that IBS is not life threatening since some patients have significant anxiety and fear that they may have cancer or another disease.
