What over-the-counter (OTC) medications can be used to treat abdominal pain and constipation?

Over-the-Counter Medications for Abdominal Pain and Constipation

For patients with abdominal pain and constipation, polyethylene glycol (PEG) is the most effective first-line over-the-counter treatment, with psyllium fiber as a beneficial adjunct therapy. 1

First-Line OTC Treatment Options

For Constipation:

1. Polyethylene glycol (PEG)

   • Dosing: 17g daily
   • Mechanism: Osmotic laxative that traps water in intestine
   • Evidence: Response to PEG has been shown to be durable over 6 months 1
   • Side effects: Bloating, abdominal discomfort, cramping
   • Cost: $10-$45 monthly
   • Key benefit: No maximum dose limit; can titrate based on symptom response

2. Psyllium (soluble fiber)

   • Dosing: 14g per 1,000 kcal intake daily
   • Mechanism: Traps water in intestine and increases stool bulk
   • Evidence: Ranked highly for effectiveness in chronic constipation 2
   • Side effects: Bloating, abdominal discomfort
   • Important caution: Must be taken with adequate fluid (at least 8oz water per dose) to prevent intestinal obstruction 3

For Abdominal Pain:

1. Peppermint oil

   • Evidence: Ranked third for effectiveness in treating abdominal pain in IBS 1
   • Side effect: Gastroesophageal reflux
   • Caution: May worsen heartburn in susceptible individuals

2. Antispasmodics (e.g., hyoscine)

   • Mechanism: Relax intestinal smooth muscle
   • Evidence: Effective for global symptoms and abdominal pain 1
   • Side effects: Dry mouth, visual disturbance, dizziness

Treatment Algorithm

Step 1: Assess predominant symptom

• If constipation is the main concern → Start with PEG
• If abdominal pain is the main concern → Start with peppermint oil or antispasmodics

Step 2: For constipation management

1. Begin with PEG 17g daily

   • Dissolve completely in 8oz water
   • Take on empty stomach for best results
   • May take 1-3 days for full effect

2. Add psyllium if needed

   • Start with 5g daily and increase gradually to 14g
   • Always take with at least 8oz water per dose
   • Take at different times than other medications (can interfere with absorption)

Step 3: For abdominal pain management

1. Try peppermint oil capsules

   • Take 30-60 minutes before meals
   • Use enteric-coated formulations to prevent heartburn

2. If ineffective, try hyoscine

   • Follow package directions for dosing
   • Be aware of anticholinergic side effects (dry mouth, blurry vision)

Additional OTC Options for Constipation

1. Magnesium oxide

   • Dosing: 400-500mg daily
   • Caution: Use with care in renal insufficiency 1

2. Stimulant laxatives (senna, bisacodyl)

   • Dosing: Senna 8.6-17.2mg daily; Bisacodyl 5-10mg daily
   • Best use: Short-term or rescue therapy
   • Caution: Not for long-term use; can cause dependence 1

Important Considerations

• Hydration: Ensure adequate fluid intake, especially when using fiber supplements 3
• Timing: PEG works within 24-48 hours; fiber supplements may take several days for full effect
• Combination therapy: PEG and psyllium can be used together for enhanced effect 4
• Dose titration: Start with lower doses and increase gradually based on symptom response
• Duration: For chronic symptoms, treatment may need to be ongoing; no maximum duration for PEG use has been established 1

When to Seek Medical Care

• If symptoms persist after 2 weeks of appropriate OTC treatment
• If severe abdominal pain, fever, or blood in stool occurs
• If constipation alternates with diarrhea (may indicate IBS requiring prescription medications)
• If weight loss or other alarming symptoms develop

For persistent symptoms despite OTC treatment, prescription options including linaclotide, plecanatide, or tricyclic antidepressants may be considered under medical supervision 1.