GI motility disorders

Question 1

Causes of motility disorders

Answer 1

ENS (missing, immature, damaged by infection, influenced by chemical substances) = neuropathic

Diseased GI muscles

Abnormalities of interstitial cells of Cajal (pacemakers)

CNS disorders

Question 2

myopathic causes of motility disorders

Answer 2

genetic (muscular dystrophy) or acquired (progressive systemic sclerosis

Question 3

Time course of swallowing

Answer 3

10 seconds for UES –> peristalsis –> LES relaxation

Question 4

Patients with dysphagia and heartburn, unresponsive to H-pump inhibitors

Answer 4

Achalasia type 1 (absence of peristalsis, no LES relaxation)

Question 5

multisystem disorder characterized by obliterative small vessel vasculitis, fibrosis of multiple organs

GI sx in 80-90% (smooth muscle atrophy, gut wall fibrosis)

Answer 5

Scleroderma/Progressive systemic sclerosis (PSS)

Question 6

Effects of Scleroderma/PSS smooth muscle atrophy and gut wall fibrosis

Answer 6

smooth muscle atrophy –> weak peristalsis and LES –> dysphagia and GERD

Question 7

Effects of unrelenting GERD

Answer 7

esophagitis –> stricture

Question 8

peristalsis preserved, chest pain and dysphagia, due to possible overreactivity of excitatory nerves or overreactivity of sm muscle response

Answer 8

spastic disorders of the esophagus (eg: Jackhammer esophagus)

Question 9

High concentration of cholinergic (excitatory) nerves in the esophagus

Answer 9

Body of esophagus –> peristalsis

Question 10

High concentration of noncholinergic (inhibitory) nerves in the esophagus

Answer 10

near the LES –> relaxation

Question 11

Physiology of gastric emptying

Answer 11

vagus –> inhibition of body tone

tonic pressure gradient –> liquid emptying

Vagally-mediated contractions –> solid emptying

Migrating motor complex –> emptying of residual solids during fasting state every 90-120 min

Question 12

Location of interstitial cells of cajal

Answer 12

proximal body along greater curvature

Question 13

discomfort or pain centered in the upper abdomen, usually related to eating

Answer 13

Dyspepsia

Question 14

Organic causes of dyspepsia

Answer 14

PUD, atypical GERD, gastric/esophageal cancer, pancreatico-biliary disorders, food/drug (NSAIDs) intolerance

Question 15

dyspepsia with no organic etiologies, impaired gastric accommodation

Answer 15

functional dyspepsia

Question 16

dyspepsia prevalence

Answer 16

20-25%

Question 17

clinical manifestations of gastroparesis

Answer 17

nausea, vomiting, early satiety (impaired gastric accommodation), postprandial abdominal distention, postprandial abdominal pain

Question 18

impaired transit of food from the stomach to the duodenum

excluded mechanical obstruction of the gastric outlet

Answer 18

gastroparesis

Question 19

major causes of gastroparesis

Answer 19

idiopathic, post-surgical (vagal nerve injury), diabetic, opiates, scleroderma, rheum, paraneoplastic

Question 20

diagnosis of gastroparesis

Answer 20

gastric emptying study (labeled egg beaters with toast, jam, water)

abnormal: retention > 60% at 2h or > 10% at 4h

Question 21

gastroparesis management

Answer 21

small, frequent meals; prokinetic/antiemetic meds; gastric electric stimulation; surgery

Question 22

Types of small bowel motility disorders

Answer 22

neuropathic, myopathic, mixed

Question 23

normal amplitude, but sustained bursts of uncoordinated phasic contractions

early return and increased frequency of MMC

Answer 23

neuropathic small bowel motility disorders

Question 24

decreased amplitude of contractions or complete lack of any motor activity

Answer 24

myopathic small bowel motility disorders

Question 25

s/sx of mech obstruction without lesion imaging --> dilation on bowel major manifestation of small intestinal dysmotility

Answer 25

chronic intestinal pseudo-obstruction (CIPO)

Question 26

major complication of CIPO

Answer 26

stasis --> bacterial overgrowth --> fermentation and malabsorption

Question 27

Symptoms of CIPO

Answer 27

nausea/vomiting, abd pain, distention, constipation, diarrhea, urinary sx

Question 28

etiologies of NEUROPATHIC small intestinal motility disorders

Answer 28

Degenerative neuropathies (eg Parkinson's), Paraneoplastic Autoimmune (anti-Hu Ab), Chagas Disease, Diabetic neuropathy

Question 29

etiologies in mixed myopathic/neuropathic small intestinal motility disorders

Answer 29

infiltrative conditions (scleroderma, amyloidosis, eosinophilic gastroenteritis), idiopathic

Question 30

childhood CIPO

Answer 30

congenital, primary absent MMC --> need IV nutrition

Question 31

function of the colon

Answer 31

transport, store, expel stool after absorbing majority of luminal fluid

Question 32

Two types of colonic motor activity

Answer 32

Haustra = low amplitude tonic/phasic contractions for mixing luminal contents High-amplitude propagated contractions (HAPCs) for propelling

Question 33

When does colonic motility increase?

Answer 33

after meal (gastrocolonic response) and on awakening

Question 34

Major causes of constipation

Answer 34

DM, Myopathy (amyloid, scleroderma), Neurogenic (Hirschprung's), dyssynergic defecation

Question 35

Colonic transit studies

Answer 35

Sitz marker, Scintigraphy, Wireless capsule

Question 36

Scintigraphy

Answer 36

isotope in delayed-release capsule dissolves in distal ileum, gamma camera scans in 4, 24, and 48h to show colonic distribution

Question 37

Sitz marker

Answer 37

24 radioopaque markers in a capsule given on Day 1 --> abd xray on Day 5

Question 38

Normal sitz marker result

Answer 38

less than 5 markers

Question 39

Sitz marker result consistent with defacatory disorder

Answer 39

more than 5 markers in recto-sigmoid

Question 40

Sitz marker result showing slow transit

Answer 40

more than 5 markers scattered throughout colon

Question 41

Area of the rectum/anal canal under voluntary control

Answer 41

puborectalis muscle, external anal sphincter

Question 42

control of internal anal sphincter muscle

Answer 42

autonomic innervation via pelvic plexus

Question 43

control of external anal sphincter muscle

Answer 43

pudendal nerve

Question 44

Purpose of anal manometry

Answer 44

evaluate incontinence and constipation

Question 45

anal monometry findings in Hirschprung's

Answer 45

absent recto-anal inhibitory reflex

Question 46

congenital absence of myenteric neurons of distal colon (neuropathic motility disorder) no recto-anal inhibitory reflex

Answer 46

Hirschprung's disease

Question 47

Pelvic floor musculature changes on defecation

Answer 47

descent of pelvic floor --> straightening anorectal angle relaxed external anal sphincter

Question 48

Conditions of pelvic floor dysfunction

Answer 48

anismus (high anal resting pressure), incomplete anal relaxation, paradoxical contraction of the pelvic floor and external anal sphincters (dyssynergia), rectal hyposensitivity, excessive perineal descent, rectocele

Question 49

Causes of pelvic floor dysfunction

Answer 49

bad toilet habits, painful defecation, obstetric or back injury, brain gut dysfunction

Question 50

diagnosis of dyssenergia

Answer 50

abnormal anorectal manometry --> paradoxical contraction of the pelvic floor and external anal sphincters

Question 51

Treatment of dyssynergia

Answer 51

biofeedback therapy

Question 52

altered esophageal peristalsis

Answer 52

achalasia, scleroderma

Question 53

altered LES relaxation

Answer 53

achalasia

Question 54

altered LES tonic contraction

Answer 54

scleroderma

Question 55

altered gastric receptive relaxation/accommodation

Answer 55

functional dyspepsia

Question 56

altered gastric emptying

Answer 56

gastroparesis, functional dyspepsia

Question 57

altered small bowel peristalsis

Answer 57

CIPO (scleroderma)

Question 58

altered colonic transit

Answer 58

scleroderma --> slow transit constipation

Question 59

sphincter dysfunction

Answer 59

Hirschprung's, dyssynergic defecation