10/12- Functional GI Disorders Flashcards
What are Functional GI disorders?
- Defined by symptoms
- Biochemical, radiologic and endoscopic tests cannot identify an organic cause of symptoms
Prevalence of Functional GI disorders?
- Adult vs. pediatric
- __% of adult Americans
- __% of office visits in GIM
- __% of referrals to GI
- 28 adult and 17 pediatric
- Highly prevalent
- 40% of adult Americans
- 20% of office visits in GIM
- 40-50% of referrals to GI
What are some of the classes of Functional GI Disorders?
- Functional Esophageal (4)
- Functional Gastroduodenal (7)
- Functional Bowel (5)
- Functional Abdominal Pain
- Functional Gallbladder and Sphincter of Oddi (3)
- Functional Anorectal Disorders (8)
What are the ROME III Criteria for IBS? (Exam Question!)
Recurrent abdominal pain or discomfort at least 3 days/mo in the last 3 mo associated with 2+ of the following:
- Improvement with defecation
- Onset associated with change in stool frequency
- Onset associated with change in form of stool
Criteria fulfilled for last 3 mo with symptom onset at least 6 mo prior to diagnosis
(Essential combo = abdominal discomfort + changes in bowel habits)
What is the most common FGID?
- Prevalence
- Epidemiology
Irritable Bowel Syndrome
- 12% in US (but not all seek healthcare)
- Women 1.5x more likely (to present, not to be affected)
- Significant impact on Quality of Life
- Significant economic impact
When is the typical onset of IBS?
- Typical onset in 20s-30s
- There is a childhood variant
- Onset decreases with age
Pathophysiology of Functional GI Disorders?
Starting point:
- Genetic factors
- Environment
Progression
- Abuse
- Acute gastroenteritis
- Other precipitating factors (stress, anxiety, depression, Abx use)
Physiologic Abnormalities
- Enteric Neuropathy (inflammation of nerve endings and disruption of conduction)
- GI motor disturbances
- Visceral hypersensitivity
- Abnormal central processing of sensations
- Psychological disturbances
Flares/exacerbations:
- Food
- Stress Result = symptoms -> consultation
Describe the brain-gut axis and the control of GI function
Central factors
- Brain activation pattern (disordered in FGIDs)
Autonomic factors
- Parasympathetic and sympathetic nervous systems (PNS and SNS)
Peripheral factors
- Serotonin signaling
- Activation of mast cells
- Altered cytokine levels
RESULTS
- Changes in GI motility
- Changes in GI secretion
- Visceral hypersensitivity
T/F: Irritable bowel syndrome and ulcerative colitis are FGIDs?
False
- IBS is a FGID, but ulcerative colitis is not
How are IBS and ulcerative colitis similar?
They have an abnormal response to normal GI stimulus
- IBS pts activated limbic and paralimbic regions; may facilitate perceptual response to the stimulus
- Pts with IBS have increased response to stress/unpleasantness than control; cannot return to same degree of relaxation even with removal of stressful stimuli
T/F: A significant number of IBS pts have anxiety or depressive disorder, but it is unlikely that IBS is secondary to these
True
Is there a degree of genetics behind IBS? (monozygotic vs. dizogytic twin studies)
Stronger association for monozygotic twins; thus, there is some genetic component
- May be mediated by hereditability of anxiety and depression
Case)
- 38 yo ME man c/o intermittent “diarrhea” and “constipation” for past 2 yrs
- Cramps, post-cibal and morning episodes
- Bloating
- No weight loss, fever, GI bleeding
- No family h/o GI cancer
- Overweight
- Diabetes on glipizide
- Normal CBC, CMP, TSH Diagnosis?
This man fulfills criteria for GFID (pain + bowel habit symptoms for > 3 mo)
- This is irritable bowel syndrome (IBS)
What are the different patient groups with IBS/constipation?
- IBS-C: IBS with constipation
- CC: chronic constipation
- IBS-M: mixed/alternating symptoms of constipation and diarrhea
What history and physical exam findings are expected in IBS?
- Site and radiation of pain
- Relief with BM
- Diarrhea/constipation
- Onset and duration: typically subacute onset
- Nocturnal symptoms
- Organic bowel disease (e.g. cancer) may produce pain that wake people from sleep
- FGID/IBS do NOT typically have nocturnal symptoms; absence of Sx that wake from sleep (sign of impaired brain-gut axis)
- Association with meals, medications
- Often the pain results from overactive gastric reflexes
- Blood from up or down
- Weight loss
- Family history
T/F: IBS commonly occurs with co-morbidities
True!
Many:
- Depression (39%)
- Migraine (37%)
- Anxiety (35%)
- Neuralgia
- Headache
- Chronic fatigue
- Chronic pain
- Fibromyositis
What signs/symptoms are NOT typical of a functional GI disorder?
- Bleeding
- Anemia
- Unexplained weight loss (>10% body wt)
- Nocturnal symptoms
- Progressive dysphagia, odynophagia
- Persistent vomiting
- Lymphadenopathy
- Abdominal mass
T/F: Organic diseases are found with increased prevalence in pt with IBS
False
- These (colorectal cancer, lactose malabsorption, thyroid dysfunction…) do not occur more with IBS
- Exception: celiac disease may be over-represented in pts with IBS who have diarrhea