Motility Disorders of the GI Tract

Question 1

Broadly, what causes motility disorder?

Answer 1

• Missing enteric nervous input
• Disease GI muscles (can be genetic defect or progressive sclerosis)
• Abnormal pacemaker cells (the interstitial cells of Cajal)
• CNS disorders

Question 2

Achalasia is __________________.

Answer 2

absence of esophageal peristalsis

Question 3

Progressive systemic sclerosis presents with what GI findings?

Answer 3

Smooth muscle atrophy (leading to weak peristalsis , GERD, and dysphagia) and gut wall fibrosis

––– predominantly a myopathic process

Question 4

Where are the interstitial cells of Cajal?

Answer 4

In the proximal body along the greater curvature of the stomach

Question 5

What is the role of the fundus?

Answer 5

It relaxes in response to food intake, thus allowing you to eat a big meal.

Question 6

Which part of the stomach does the processing?

Answer 6

The distal stomach, near the antrum

Question 7

What nerve mediates receptive relaxation and distal grinding?

Answer 7

The vagus nerve (in response to LES relaxation); hence, patients with vagotomies often have failure of gastric accommodation.

Question 8

Define gastroparesis.

Answer 8

(n.) stomach paralysis; can be caused by muscle weakness or obstructive disorders

Question 9

What percent of radiolabeled EggBeaters is considered abnormal retention?

Answer 9

• Greater than 60% at two hours

- Greater than 10% at four hours (greater than 35% is considered severe)

Question 10

What is the hallmark of GI motility disorders?

Answer 10

Intestinal pseudo-obstruction – signs/symptoms of intestinal obstruction without a lesion obstructing flow of intestinal contents

Question 11

What major small intestine complication should you worry about in someone with chronic intestinal pseudo obstruction?

Answer 11

Stasis can lead to bacterial overgrowth, which can lead to malabsorption, fermentation

Question 12

CIPO has a ___________ prognosis in children. What usually causes it?

Answer 12

poor (1/3 die before age 1!); it is generally congenital

Question 13

Low-amplitude contractions in the colon produce ________________.

Answer 13

mixing

Question 14

High-amplitude contractions in the colon produce _______________.

Answer 14

propulsion

Question 15

Describe the process of Sitz markers.

Answer 15

You give someone a capsule containing 24 radio opaque capsules and then x-ray their abdomen five days later; less than five markers is considered normal. It is used to evaluate colonic transit.

Question 16

What causes Hirschsprung’s?

Answer 16

Congenital absence of the myenteric neurons of the distal colon, resulting in absence of the inner-anal sphincter reflex. (It’s normally supposed to relax in response to arrival of feces.)

Question 17

Small frequent meals low in insoluble fiber and fats is a treatment for ________________.

Answer 17

gastroparesis

Question 18

Describe the setup for recording esophageal manometry.

Answer 18

It is a nasogastric catheter placed down the esophagus that records pressure every one centimeter while the patient swallows water.

Question 19

Achalasia results from ________________.

Answer 19

inflammatory destruction of the myenteric nerve plexus of the esophagus – predominantly the nitric-oxide-producing inhibitory neurons (sparing the cholinergic excitatory)

Question 20

True or false: achalasia usually presents suddenly.

Answer 20

False. The progression is gradual, with many patients not seeking treatment until years of symptoms.

Question 21

What percent of patients with scleroderma have GI involvement?

Answer 21

90

Question 22

How can you resolve scleroderma and achalasia?

Answer 22

Those with scleroderma usually have a weak LES pressure, while those with achalasia have a normal or even overactive LES pressure.

Question 23

Contrast the roles of the proximal and distal portions of the stomach.

Answer 23

Proximal: relaxes in response to filling so as to accommodate meals

Distal: contracts to mechanically grind food; empties into the duodenum

Question 24

What are some classic causes of gastroparesis?

Answer 24

• Vagotomy
• Diabetes (autonomic neuropathy)
• Medications
• Neurologic disorders (MS, Parkinson’s, stroke)

Question 25

True or false: the MMC phases occur in transplanted small bowel.

Answer 25

True. Only the enteric nervous system is needed; extrinsic innervation (i.e., the vagus nerve) is not needed

Question 26

Chagas disease (Trypanosoma infection) can lead to what bowel problem?

Answer 26

Chronic intestinal pseudo-obstruction

Question 27

Most of the colonic contractions are which type of movement?

Answer 27

Segmental (95%)

Peristaltic (5%)

Question 28

The _____________ reflex is lost in those with Hirschsprung’s.

Answer 28

internal anal sphincter relaxation

Question 29

What is the characteristic pattern of neuropathic small-bowel disorders?

Answer 29

Normal amplitude contractions, but uncoordinated

Increased frequency of MMC

Question 30

Biofeedback therapy is helpful for ____________.

Answer 30

dyssynergia