Constipation in Adults

Background

• Constipation is unsatisfactory defecation characterized by infrequent stools and/or difficult stool passage. It is common, with prevalence estimates up to 27% of adults. It is more common in adults > 65 years old.
• Primary constipation may be functional, related to slow transit, or associated with defecatory/pelvic floor dysfunction.
• Secondary constipation can be due to diet, lifestyle, pregnancy, advanced age, medications, or underlying medical conditions.

Evaluation

• Functional constipation is defined (Rome IV Criteria) by the presence of symptoms for at least 2 of past 3 months with symptom onset ≥ 6 months before diagnosis:
  • straining during ≥ 25% of defecations
  • lumpy or hard stools during ≥ 25% of defecations
  • feeling of incomplete evacuation during ≥ 25% of defecations
  • feeling of anorectal obstruction or blockage during ≥ 25% of defecations
  • manually facilitating defecation; and < 3 defecations/week
  • loose stools rarely present without laxatives
  • criteria for irritable bowel syndrome is not sufficiently met. For example abdominal pain or discomfort is not relieved by defecation or associated with changes in bowel frequency or stool form for at least 3-6 months (although abdominal pain and/or bloating may be present, they are not predominant symptoms).
• Do not perform diagnostic testing in patients who do not meet general screening indications without alarm signs and symptoms or findings suggestive of a secondary cause (Strong recommendation).
• Initial testing (guided by signs and symptoms) could include complete blood count, electrolytes, calcium, glucose, thyroid function tests, fecal occult blood test, x-ray or CT scan to rule out obstruction, and colonoscopy for patients with alarm symptoms or who otherwise require screening.
• For refractory constipation, consider colonic transit studies and anorectal manometry (Weak recommendation).

Management

• Encourage dietary modification (with increased fiber such as fresh fruists and vegetables, legumes or whole grains) as initial management for primary functional constipation (Strong recommendation).
• If constipation is chronic, offer laxative therapy with one of:
  • osmotic laxatives polyethylene glycol (PEG) (Strong recommendation) or lactulose 10-20 g (Strong recommendation) daily
  • lactulose 10-20 g/day (Strong recommendation)
  • stimulant laxatives sodium picosulfate or bisacodyl (Strong recommendation) as well as senna, although there is less evidence for the long term effects of stimulant laxatives.
• If laxatives do not provide adequate relief, offer drug therapy with one of:
  • secretagogues: lubiprostone 24 mcg orally twice daily (Strong recommendation) , linaclotide 145 mcg daily (Strong recommendation) or plecanatide 3 mg daily.
  • prokinetic: prucalopride 2 mg daily in patients with severe chronic constipation (Strong recommendation) .
• For opioid-induced constipation also consider mu-opioid antiagonists naldemedine, methylnaltrexone, or naloxegol.
• Consider offering probiotics.
• Offer electroacupuncture or a related therapy to patients with chronic, severe functional constipation.
• For constipation related to defecatory disorders/pelvic floor dysfunctoin, consider biofeedback aided pelvic floor retraining (Weak recommendation)..
• For slow-transit constipation unresponsive to other therapy, consider total abdominal colectomy with ileorectal anastomosis (Weak recommendation).
• For management of acute episodes of constipation see Fecal Impaction.