Constipation

Constipation Results in 2.5 million doctor visits per year
2 – 28% prevalence in general population

Patients are typically seen by:

  • Family practitioners (31%)
  • Internists (20%)
  • Pediatricians (15%)
  • Gastroenterologist (4%)

$400 million spent on laxatives annually (1991)

Other Names for Constipation:

  • Infrequent bowel movements
  • Rectal outlet obstruction
  • Excessive straining
  • Rectal or anal blockage
  • Rectal or pelvic pressure
  • Incomplete evacuation

Constipation Counselling Sheet

Mechanisms of Fecal Continence

In order to understand constipation one must understand why people can hold stool. There are multiple factors that affect continence.

  • Colonic factors
  • Stool volume
  • Stool consistency
  • Anorectal factors
  • Capacity/compliance of rectum
  • Anal seal of vascular cushions
  • Muscular factors
  • Sphincteric/pelvic floor function
  • Intact anal sphincter
  • Neurological factors
  • Rectal sensation
  • Normal mentation
  • Intact innervation/reflexes

Process of Defecation

The process of defecation is very complex. It is as follows:

  • Entry of stool in the vault
  • Internal sphincter relaxes
  • Semi-voluntary Valsalva
  • Increase intrathoracic/-abdominal pressure
  • External sphincter relaxes
  • Pelvic floor descends

If any of these are abnormal or in a different order, defecation can be difficult.

Causes of Constipation

  • Endocrine diseases
  • Metabolic disorders
  • Neurologic disorders
  • Surgery
  • Dietary/Activity abnormalities
  • Collagen vascular disorders
  • Pharmacologic agents
  • Obstructive bowel diseases
  • Functional disorders
  • Primary or idiopathic
  • Global motility disorder
  • Outlet obstruction

Primary Constipation

There are different types or forms of constipation. These different types have certain characteristics.

  • Colonic Intertia
    • Infrequent stools
    • Change in consistency
  • Normal Transit Constipation
    • Normal frequency
    • Normal consistency
    • “Feel constipated” or “bloated”
  • Outlet Obstruction
    • Normal frequency
    • Normal consistency
    • Difficulty evacuating

Work-up of Constipation

The work-up of constipation can include many tests. An extensive work-up allows the surgeon to choose the right treatment plan for the individual patient. The work-up can include the following:

History and Physical

Anal Physiology Testing

  • Anal manometry
  • Rectal sensation testing
  • Recto-anal inhibitory reflex testing
  • Balloon evacuation
  • Electromyography

Labs/Stool Studies

Radiology

  • Sitz mark study (colonic transit study)
  • Defecography
    • Fluoroscopic
    • Magnetic resonance
  • Gastric motility
  • Upper gastrointestinal series and small bowel follow through
  • Barium enema
  • Balloon proctography
  • Fecoflowmetry
  • Peritoneography

Colonoscopy

Upper Endoscopy

Pelvic Floor Symptoms

  • Pelvic/vaginal pressure
  • Dyspareunia (painful intercourse)
  • Dragging/drawing vaginal sensation
  • Urinary incontinence
  • Difficulty emptying bladder
  • Repositioning body to empty bladder
  • Constipation – Infrequency, Straining
  • Fecal incontinence
  • Incomplete emptying
  • Bulging
  • Pain/pressure
  • Bleeding
  • “blockage”

Sitz Mark Test (colonic transit time test)

  • Good as a screening test
  • Different techniques are used
  • Previously stool was X rayed for markers
  • Segmental transit times can be obtained
  • Part of workup for all constipation
  • Cheap
  • Easy to use & easy to read
  • Used with UGI&SBFT and/or gastric emptying study
  • Confirms an outlet obstruction in 75–92% of patients with defecographic non-relaxation

Fluoroscopic Defecography

  • Evacuation proctography, video defecogram
  • Cineradiology first used in 1960’s
  • Primarily assesses anatomical relationships
  • Abnormal in 50% of asymptomatic patients

Anorectal Manometry

  • Assesses the physiologic interaction of rectum & anus
  • Protocols: Static, Continuous pull-through, Station pull-through protocols
  • Obviates needle EMG

Treatment of Constipation

  • Dietary changes, fiber, increased fluids
  • Exercise
  • Laxatives / enemas
  • Motility agents
  • Biofeedback / physical therapy
  • Medication adjustments
  • Systemic disease treatment
  • Surgical correction
    • Pelvic floor repair
    • Colectomy
    • Rectopexy
    • Rectocele repair
    • Botox injection