Disorders of GI Motility

Diagnosis

• If defecation disorders are ruled out (or if symptoms persist despite normalization of defecation disorders), obtain a colonic transit study

• Up to 50% of patients with defecatory disorders also have slow colonic transit

Signs and Symptoms

• sense of incomplete evacuation 

• significant straining with bowel movements

• need to apply perineal pressure

• rectal exam showing...

  • high resting sphincter tone

  • paradoxical anal contraction with simulated defecation

Motility Study Findings

• anorectal manometry 

  • inadequate rectal propulsive forces

  • inadequate anal relaxation with simulated defecation

  • absent rectoanal inhibitory reflex (RAIR)

    • seen in Hirschsprung's disease or megarectum

  • Defecation index = maximum rectal pressure during attempted defecation/minimum anal residual pressure during attempted defecation

    • normal defecation index is > 1.5

• Balloon expulsion testing

  • balloon expulsion time > 2 min is abnormal

  • absent rectoanal inhibitory reflex (RAIR)

    • seen in Hirschsprung's disease or megarectum

  • Defecation index = maximum rectal pressure during attempted defecation/minimum anal residual pressure during attempted defecation

    • normal defecation index is > 1.5

• when anorectal manometry and balloon expulsion testing are discordant or inconclusive, defecography is the next best step

Treatment

• Biofeedback therapy

  • pelvic floor retraining

    • training patients to relax their pelvic floor muscles during straining and to correlate relaxation and pushing to achieve defecation. Restore normal pelvic floor coordination

  • improves symptoms in >70% of patients

  • if patients fail to improve, repeat balloon expulsion

    • if abnormal, obtain an MR defecography to assess for significant structural abnormalities 

• Laxatives are not the correct therapy for dyssynergia

Definition

• gastric pylorus dysfunction

  • present in ~30%

Signs and Symptoms

• nausea

• vomiting

Treatment

• gastric pylorus botulinum toxin injection

  • lasts for ~2 mo

• G-POEM

• Transpyloric stent placement

  • high risk of stent migration

(***Review/update with most recent ACG guidelines***)

Endoscopic Findings

• wireless motility capsule

Imaging Findings

• radiopaque marker study - retained markers on day 5

• gastric emptying scan

  • may be necessary in those with delayed colonic transit despite maximal medical therapy

Manometry Findings

• Colonic Manometry

  • reserved for those who do not respond to standard medical therapy with normal gastric emptying

Endoscopic Findings

• High resolution manometry

  • premature contractions

  • normal IRP sphincter

Endoscopic Findings

• High resolution manometry

  • hypercontractile contractions

  • normal IRP sphincter

Definition

• impaired function or proximal striated muscles in the upper esophagus and pharynx

Signs and Symptoms

• coughing or chocking during meals

• nasal regurgitation

Risk Factors

• Polymyositis

Versus

• Systemic sclerosis

  • affects the smooth muscle in the distal 2/3 of the esophagus leading to incompetent lower esophageal sphincter

  • often presents with peptic stricture in the setting of reflux

Definition

• colonic dilation

• no clear evidence of mechanical obstruction

Risk Factors

• post-operative

Imaging

• colonic dilation without identifiable transition point

Treatment

• IV neostigmine

Definition

• Relaxation of the internal anal sphincter due to distention of the rectum

• Occurs in conjunction with voluntary external anal sphincter contraction