Motility Disorders Flashcards
Causes of motility disorders
- neuropathic = peripheral neurologic problem
- ENS is missing, immature, damaged bu infection, influenced by chemical substances
- myopathic = diseased GI muscles
- genetic defect (muscular dystrophy) or acquired (progressive systemic sclerosis)
- CNS disorders
Characteristics of Scleroderma (Progressive Systemic Sclerosis (PSS))
- Multisystem disorder characterized by:
- Obliterative small vessel vasculitis
- Connective tissue proliferation with fibrosis of multiple organs
- GI manifestations in 80-90%
- The principal pathological abnormalities of the GI tract consist of smooth muscle atrophy and gut wall fibrosis.
GI symptoms of Scleroderma/PSS
- Smooth Muscle Atrophy & Gut Wall Fibrosis
- Myopathic (predominantly) process
- Esophageal Manifestations
- Smooth Muscle Atrophy ==> Weak Peristalsis ==> Dyspahgia
- Smooth Muscle Atrophy ==> Weak LES ==> GERD
- Unrepentant GERD ==> Esophagitis ==> Stricture
- Dx of Esophageal Disease via Esophageal manometry
Physiology of gastric emptying
–Receptive relaxation (vagally mediated inhibition of body tone)
–Liquid emptying by tonic pressure gradient
–Solid emptying by vagally-mediated contractions
–Residual solids emptied during non-fed state by MMC every 90-120 minutes
Characteristics of functional dyspepsia (FD)
- Dyspepsia: Discomfort or pain centered in the upper abdomen
- Includes postprandial heaviness, early satiety, epigastric pain or burning
- considered FD when dyspepsia occurs w/out identifiable organic etiology
- Gastric motility problem:
- stomach normally serves as resevoir after meal ingestion
- 40% of FD pts have impaired gastric accommodation
Organic etiologies of dyspepsia
- PUD
- atypical GERD
- gastric/esophageal cancer
- pancreatico-biliary disorders
- food/drug (NSAIDs) intolerance
Characteristics of gastroparesis
- Gastroparesis = “stomach paralysis”
- Impaired transit of food from the stomach to the duodenum
- excluding mechanical obstruction
- clinical manifestations
- Nausea
- Vomiting
- Early satiety
- Postprandial abdominal distention
- Postprandial abdominal pain
Major causes of gastroparesis
- Idiopathic
- Post-surgical (vagal nerve injury)
- Diabetic
- Medication-related (opiates)
- Others
- Paraneoplastic
- Rheumatologic
- Neurologic
- Myopathic
Characteristics of gastric scintigraphy
- evaluates gastric emptying
- Low fat EggBeaters radiolabelled with 1 mCi Technetium 99
- Microwaved and served with toast, jam and water
- Abnormal: retention >60% at 2 hr or >10% at 4 hr
- e.g. gastroparesis
Characteristics of chronic intestinal psuedo-obstruction (CIPO)
- 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
- Major Manifestation of Small Intestinal Dysmotility
- Small Intestinal Bacterial Overgrowth a complication of CIPO
Sx of CIPO
–N/V (83%)
–Abd. Pain (74%)
–Distention (57%)
–Constipation (36%)
–Diarrhea (29%)
–Urinary Sx (17%)
Etiologies of CIPO/small intestinal motility disorders
•Neuropathic
–Degenerative Neuropathies (eg Parkinon’s)
–Paraneoplastic Autoimmune (anti-Hu Ab)
–Chagas Disease: parasite Trypanosoma cruzi
–Diabetes associated (neuropathy)
•Mixed Myopathic and Neuopathic
–Infiltrative Conditions: Scleroderma, Amyloidosis, Eosinophilic Gastroenteritis
–Idiopathic
Major metabolic, myopathic, neurogenic, other causes of constipation
- metabolic: DM
- myopathy: amyloid, scleroderma
- neurogenic: Hirschsprung’s
- Other
- drus
- dyssynergic defecation
Colonic Transit Studies
- sitz marker
- scintigraphy
- wireless capsule
Sitz marker study characteristics
•24 radioopaque markers in a capsule given on Day 1.
•Plain abdominal xray on Day 5.
–< 5 markers normal
–> 5 markers in recto-sigmoid suggests defecatory disorder
–>5 markers scattered throughout colon = slow transit
Scintigraphy colonic transit study characteristics
–Isotope in delayed-release capsule dissolves in alkaline pH of distal ileum
–Gamma camera scans in 4,24, and 48 hours to show colonic distribution
Anatomy of the rectum and anal canal
- puborectalis muscle = striated (volitional)
- internal anal sphincter muscle =
- circular smooth muscle
- autonomic innervation: pelvic plexus
- external anal sphincter muscle =
- striated muscle (volitional)
- innervation: pudendal nerve
Characteristics of anal manometry
- Anal manometry provides comprehensive information regarding anal sphincter function at rest and during defecatory maneuvers
- Evaluation of incontinence: Resting and volitional squeeze, cough reflex test, rectal sensation testing
- •Evaluation of constipation:
- –Anal resting pressure
- –Attempted defecation lying left lateral
- –Simulated defecation on commode with 50cc balloon
- –Recto-anal inhibitory reflex (absent in Hirschsprung’s)
- –Rectal sensation testing
Procedure of anal manometry
- manometry probe with 6 sensors arranged radially and spaced at 1cm, 2cm, 3, 4, 5, and 8 cm with a balloon at the end fo the probe.
- attached to a pressure recording device
- Patient is placed in the left lateral position and a lubricated manometry probe is inserted with the most distal 1cm sensor located 1cm from the anal verge. Then 5 minutes of rest to allow sphincter tone to return to baseline.
- Various tests for anal sphincter fxn
Characteristics of Hirschsprung’s Disease
- Congenital absence of myenteric neurons of the distal colon (Neuropathic Motility Disorder)
- No reflex inhibition of the IAS following rectal distention (No Recto-anal inhibitory reflex)
- ==> abnormal barium enema study: narrowed distal and dilated proximal
- ==> abnormal anal manometry
Characteristics of pelvic floor dysfunction
•Inability to coordinate the abdominal, rectoanal and pelvic floor muscles during defecation
–Anismus (high anal resting pressure)
–Incomplete anal relaxation
–Paradoxical contraction of the pelvic floor and external anal sphincters (dyssynergia)
–Rectal hyposensitivity
–Excessive perineal descent
–Rectocoele
•Causes: Bad toilet habits, Painful defecation, Obstetric or back injury, Brain gut dysfunction
