Constipation Management

Initial Assessment and Approach

The goal of constipation management should be achieving one non-forced bowel movement every 1-2 days 3

The American Gastroenterological Association recommends polyethylene glycol (PEG) 17g once daily mixed in 8 ounces of water as first-line pharmacological treatment, combined with lifestyle modifications including adequate fluid intake and increased physical activity 1, 2
PEG increases complete spontaneous bowel movements by approximately 2.9 per week compared to placebo 1
Response to PEG has been shown to be durable over 6 months 1, 2
Patients with low fluid intake are most likely to be constipated, so fluid supplementation is particularly important for those with low baseline intake 1, 2

Increasing fluid intake to 1.5-2.0 liters per day significantly enhances the effectiveness of fiber and laxative therapy 1, 2
Regular physical activity within the patient's capabilities is recommended 4
Optimize toileting habits: attempt defecation twice daily, preferably 30 minutes after meals, and strain no more than 5 minutes 5, 4

For mild constipation, a trial of fiber supplementation can be considered before PEG or in combination with it 1, 2
Psyllium is the fiber supplement with the best evidence 1, 2
Fiber supplementation should only be used if the patient has adequate fluid intake (at least 1.5-2 liters daily) and is ambulatory 6, 4

If PEG alone is insufficient after 7 days, bisacodyl 10-15 mg once daily can be added to the regimen 3
Alternative: Senna 2 tablets twice daily 3
Lactulose can be substituted if PEG is not tolerated 4
Avoid magnesium-based laxatives (magnesium hydroxide) in patients with any renal impairment due to risk of hypermagnesemia 5, 6, 4

Do not use docusate (stool softeners) as monotherapy - there is no proven benefit and it should not be considered first-line treatment 7
Do not use bulk-forming laxatives or fiber supplements in patients with low fluid intake - this increases the risk of mechanical obstruction 6, 4