Nutrition

Bulk Laxative

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Bulk Laxative, Bulk-Forming agents, Psyllium, Metamucil, Methylcellulose, Citrucel, Polycarbophil, Fibercon

  • See Also
  1. Dietary Fiber
  • Indications
  1. Constipation
  2. Irritable Bowel Syndrome
  3. Diverticulosis
  4. Hemorrhoids
  5. Hypercholesterolemia
  6. Obesity
  • Background
  1. Take at least 2 hours before or 2 hours after other medications
  2. All of these should be mixed with a large glass of water, and then followed with a second glass of water
  3. Onset of bowel stimulation is typically 12 to 72 hours
  • Precautions
  1. Use with 64 oz/day (>1.8 Liters/day) non-caffeinated fluid
  2. Poorly tolerated in atonic colon (e.g. Megacolon)
  • Medications
  • Bulk-Forming agents (Bulk Laxative)
  1. Psyllium (Metamucil)
    1. Nondigested plant cell wall absorbs water in the Gastrointestinal Tract, promoting stool softening
    2. Adults (and age >=12 years): 10 grams per day
      1. Take 1-2 tsp (or 2.4 grams soluble fiber) in 8 ounces of water or juice orally three times daily
      2. Follow each dose with another glass of fluid
    3. Child (ages 6 to 11 years)
      1. Give 1.2 grams soluble fiber orally in 4 to 8 ounces of water or juice orally three times daily
      2. Follow each dose with another glass of fluid
  2. Methylcellulose (Citrucel)
    1. Derived from cellulose, with similar activity to Psyllium
    2. Nondigested Carbohydrate absorbs water in the Gastrointestinal Tract, promoting stool softening
    3. Adults (and age >=12 years): 6 grams per day
      1. Take 2 grams in 8 ounces liquid orally three times daily
  3. Calcium Polycarbophil (Fibercon)
    1. Synthetic bulk agent containing polyacrylic acid
    2. Dose: Two 625 mg tablets orally three times daily
  • Medications
  • Alternative
  1. See Dietary Fiber
  2. Dietary sources with as much fiber at 10% of cost
    1. Wheat bran, oat bran or all-bran cereal
    2. Lima, Navy, Kidney and baked beans
  • Adverse Effects
  1. Bowel Obstruction
  2. Abdominal cramping or Gas (bloating, Abdominal Distention, Flatulence)
    1. More common if started too quickly with high dosing
    2. Reduced by gradually increasing fiber intake to 225-30 grams per day
    3. Side effects more likely with dyssynergic Defecation
    4. Side effects are more common with insoluble fiber
      1. Insoluble fiber examples include (Methylcellulose, Citrucel, wheat bran)
      2. In contrast, soluble fiber (psyillium, Metamucil, oat bran) is associated with less gas
  • Drug Interactions
  1. May interfere with absorption of medications
    1. Do not take medications at the same time as Psyllium
    2. Space Psyllium several hours apart from medications
  2. Agents known to be affected
    1. Carbamazepine (Tegretol)
      1. Etman (1995) Drug Dev Ind Pharm 21:1901-6 [PubMed]
    2. Lithium
      1. Perlman (1990) Lancet 335:416 [PubMed]