GI motility disorders Flashcards
What innervates the gut wall?
parasympathetic nerves from vagus nerve and pelvic nerve innervate the longitudinal muscle directly (pelvic only) and the myenteric plexus which innervates the circular muscle and submucosal plexus, which innervates the muscularis mucosaa and endocrine/secretory cells in mucosa
List processes that cause motility disorders
enteric nervous system problems (neuropathic), diseased GI muscles (myopathic), abnormalities of interstitial cells of Cajal (pacemaker) or central nervous system disorders
How long does it take for a swallowed bolus to reach the stomach
5-10 seconds
Components of esophageal function test
upper esophageal sphincter relaxation, proximal peristalsis (striated), propagation of swallow along esophageal body, distal peristalsis (smooth muscle), post-deglutitive lower esophageal sphincter relaxation
what does an esophageal function test show in pt with dysphagia and heartburn
UES relaxation but no peristalsis or LES relaxation
What is Scleroderma/Progressive Systemic Sclerosis (PSS)
Multisystem disorder characterized by: Obliterative small vessel vasculitis and Connective tissue proliferation with fibrosis of multiple organs. 80-90% have GI issues, including smooth muscle atrophy and gut wall fibrosis
Esophageal manifestations of Scleroderma/Progressive Systemic Sclerosis (PSS)
Smooth Muscle Atrophy > Weak Peristalsis >Dyspahgia.
Smooth Muscle Atrophy > Weak LES > GERD.
Unrepentant GERD > Esophagitis > StrictureSmooth Muscle Atrophy > Weak Peristalsis >Dyspahgia.
Smooth Muscle Atrophy > Weak LES > GERD.
Unrepentant GERD > Esophagitis > StrictureSmooth Muscle Atrophy > Weak Peristalsis >Dyspahgia.
Smooth Muscle Atrophy > Weak LES > GERD.
Unrepentant GERD > Esophagitis > Stricture
How are esophageal diseases diagnosed
esophageal manometry
scleroderma esophageal manometry results
UES relaxation but no peristalsis or LES relaxation
describe gastric motility patterns
retropulsion and receptive relaxation (gastric emptying)
describe physiology of gastric emptying
receptive relaxation occurs by vagally mediated inhibition of body tone. Liquid emptying occurs by tonic pressure gradient and solid emptying occurs by vagally mediated contractions. Residual solids are emptied during non fed state by MMC every 90-120 minutes
What is the gastric pacemaker
Interstitial cells of cajal located in proximal body along greater curvature.
Function of fundus/ proximal body and antrum/distal body
fundus/proximal body: storage. Antrum/distal body: processing and emptying
Factors contributing to gastric reservoir function
receptive relaxation and accommodation(where smooth muscle relaxation is elicitd by mechanical distention of the stomach and gastric mechanoreceptors)
What is functional dyspepsia
•Discomfort or pain centered in the upper abdomen. Includes postprandial heaviness, early satiety, epigastric pain or burning. No organic etiologies (such as PUD, atypical GERD, gastric cancer, pacreatico-biliary disorders, food/drug intolerance)
gastric motility in functional dyspepsia
40% have impaired gastric accomodation and delayed gastric emptying (caused by gastric dysrhytmias and ineffective antropyloroduodenal contraction patterns)
What is gastroparesis
stomach paralysis. Impaired transit of food from the stomach to the duodenum. Mechanical obstruction of the gastric outlet excluded
Clinical features of gastroparesis
Nausea, Vomiting, Early satiety, Postprandial abdominal distention, Postprandial abdominal pain
Causes of gastroparesis
idiopathic, post infectious, post-surgical (ie. vagal nerve injury), diabetes, medications (opiates), paraneoplastic, rheumatologic, neurologic, myopathic
How is gastroparesis diagnosed
gastric empyting study: Abnormal: retention >60% at 2 hr or >10% at 4 hr
gastroparesis management
Small frequent meals, low fat, low fiber, glucose control in diabetics, prokinetic agents, antiemetics, gastric electric stimulation and/or surgery
describe normal motility in small intestine
Fed state: primary motility is segmentation, pacemaker cells facilitate 9-12 contractions per minute and total transit time is 3-5 hrs. Fasted state: migrating motor complex facilitates sequential short peristaltic waves from stomach caudally. This sweeps the gut between meals
compare neuropathic vs myopathic small bowel motility disorders
Neuropathic: Normal amplitude but sustained bursts of uncoordinated phasic contractions. Early return of MMC. Increased frequency of MMC. Myopathic: Decreased amplitude of contractions or complete lack of any motor activity
What is Chronic Intestinal Psuedo-Obstruction
•Signs and symptoms of mechanical obstruction of the small bowel without a lesion obstructing flow of intestinal contents. Characterized by the presence of dilation of the bowel on imaging. Manifestation of small intestinal dysmotility
