Management of Constipation in a Patient Who Has Not Had a Bowel Movement for 7 Days
For a patient who has not had a bowel movement for 7 days, immediate treatment with polyethylene glycol (17g with 8oz water twice daily) as first-line therapy is recommended due to its effectiveness and minimal side effects. 1
Initial Assessment
- Rule out serious causes of constipation including impaction, obstruction, hypercalcemia, hypokalemia, hypothyroidism, and diabetes mellitus 2, 1
- Perform digital rectal examination to check for impaction and assess for pelvic floor dysfunction 1
- Evaluate for alarm symptoms requiring further investigation: age >50 years, gastrointestinal bleeding, new-onset constipation, palpable abdominal/rectal mass, weight loss, anemia 3
First-Line Treatment Options
- Polyethylene glycol 17g dissolved in 4-8 ounces of water twice daily 1, 4
- Stimulant laxative such as bisacodyl (10-15 mg, 2-3 times daily) or senna with a goal of one non-forced bowel movement every 1-2 days 2, 5, 6
- Ensure adequate fluid intake and encourage physical activity when appropriate 2, 7
- Consider dietary modifications to increase fiber intake, though supplemental fiber alone is unlikely to resolve established constipation 2, 8
If Constipation Persists After Initial Treatment
- Check for impaction; if present, consider glycerine suppositories or manual disimpaction 2
- Add osmotic laxatives such as lactulose (30-60 mL daily), magnesium hydroxide (30-60 mL daily), or magnesium citrate 2
- Consider rectal bisacodyl suppository daily 2
- Fleet, saline, or tap water enema may be needed for immediate relief 2, 1
For Severe or Persistent Constipation
- Consider adding a prokinetic agent such as metoclopramide (10-20 mg PO three times daily) 2
- For opioid-induced constipation that hasn't responded to standard laxative therapy, methylnaltrexone 0.15 mg/kg subcutaneously (no more than once daily) may be effective 2
- For persistent constipation, combination therapy with different classes of laxatives may be more effective than single agents 2, 1
Important Cautions
- Do not use bisacodyl for more than one week without medical supervision 5
- Do not use polyethylene glycol for more than 7 days without consulting a doctor 4
- Discontinue use and seek medical attention if rectal bleeding occurs or if no bowel movement occurs after using laxatives, as these may indicate a serious condition 5
- Water-soluble fibers alone (such as psyllium) have limited effect on stool weight and may not be appropriate as sole treatment for significant constipation 1, 8
- Stool softeners alone without stimulant laxatives are generally ineffective for treating significant constipation 1
Follow-up
- Monitor for treatment response with the goal of one non-forced bowel movement every 1-2 days 2, 1
- If constipation persists beyond 7 days despite appropriate treatment, further evaluation may be necessary 4, 9
- Consider colonoscopy if alarm symptoms are present or if constipation is new-onset, especially in patients over 50 years of age 3