Constipation%20in%20adults%20-%20chronic%20functional Diagnosis

• Thorough history and physical exam in many cases can rule out most secondary causes of constipation eg colonic diseases (anal fissure, hemorrhoids, cancer, proctitis, stricture), neurologic disorders (spinal cord lesions or injury, parkinsonism, multiple sclerosis), disturbances in metabolism (diabetes mellitus, hypothyroidism, hypercalcemia), drug side effects (antispasmodics, iron and calcium supplements, opioids), or other conditions (depression, immobility, cardiac disease, cognitive impairment, scleroderma)

• Current bowel regimen and pattern
  • Use of Bristol stool scale may help in better characterizing bowel habits and fecal consistency
• Associated abdominal pain or distress that is less severe and not the main symptom as compared with IBS
  • IBS may be suggested by a history of predominant abdominal pain, bloating, malaise, upper GI (eg dyspepsia, heartburn) and urinary symptoms, increased rectal sensation, anxiety and depression
• Toileting habits, eg unusual postures on toilet to ease stool expulsion
• Posterior vaginal pressure, perineum support or digitation of rectum to ease rectal release
• Failure to discharge enema fluid
• Pelvic floor dysfunction may be suggested by prolonged and excessive straining prior to elimination; when evacuatory defects are pronounced, soft stools or even enema fluid is difficult to pass; need for perineal or vaginal pressure or digital evacuation is also indicative
  • Evacuatory disorders do not respond well to laxatives
• Medication history including products used to relieve constipation or the use of opiates and codeine
• Inquire also on patient’s obstetric and surgical history, diet and fluid intake, lifestyle (activity level) and occupation

• Should be done to rule out diseases to which the constipation is secondary, eg abdominal mass from an organic cause, dry skin from hypothyroidism

Rectal Exam 

• Performed with patient in left lateral position
• Inspect perianal area to look for fissures, fistulas, external hemorrhoids
• Determine extent of perineal descent while patient, at rest, bears down
  • Reduced descent may indicate inability to relax pelvic floor muscles during defecation
  • Excessive descent may show laxity of the perineum which may be caused by childbirth or several years of straining

Digital Exam of the Rectum

• Check for fecal impaction, anal stricture or fissure, internal hemorrhoids, anorectal masses, rectoceles or rectal prolapse
• Lax anal orifice may suggest neurologic disorder or trauma as the cause of impaired sphincter function
• Inability or difficulty in inserting the finger into the anal canal may suggest elevated anal sphincter tone at rest or anal stricture
• Spasm of pelvic floor may be suggested by tenderness at the posterior aspect of the rectum
• Refer patients with normal digital rectal exam findings and persistent symptoms for anorectal testing to rule out defecatory disorders

• In patients presenting with constipation without alarm symptoms, there is not sufficient data to make recommendations for routine use of colonoscopy, flexible sigmoidoscopy, barium enema, thyroid function tests, serum calcium, etc
  • A complete blood count (CBC) may be done to evaluate chronic constipation in the absence of other signs and symptoms
  • Specific metabolic diagnostic tests (eg thyroid and renal function tests, fasting blood sugar, calcium) may be performed in patients with additional signs or symptoms of an organic disorder
• Routine colon cancer screen tools are recommended in all patients >50 years old
  • >40 years in areas with high prevalence of gastric cancer
• In a patient who presents with alarm symptoms or is >50 years of age, objective testing with blood biochemistry, imaging studies or colonoscopy is needed to verify the diagnosis, exclude organic disease, identify underlying pathophysiology in refractory cases and determine corresponding treatment
  • Flexible sigmoidoscopy and colonoscopy can identify lesions that narrow or occlude the bowel
• Colonoscopy is preferred in patients with iron-deficiency anemia, positive guaiac stool test, or 1st-degree relative with colon cancer
• CT colonography, a less invasive alternative to colonoscopy, has a sensitivity similar to or better than that of double-contrast barium enema in detecting polyps and colon cancer
• If extracolonic and mechanical causes of constipation are ruled out with lab tests and colorectal imaging, then a complete physiologic evaluation may be useful, although the interpretation should be guarded as patient cooperation is critical
  • Eg anal manometry, balloon insertion, defecography and colonic transit studies