Metamucil is a dietary supplement that is sold over-the-counter. It is commonly used to treat constipation and diarrhea and can also help lower cholesterol. Metamucil is 100 percent psyllium husk fiber, a soluble fiber that provides regularity 4. Depending on the cause of your diarrhea, using Metamucil may or may not be helpful. For example, certain illnesses, such as the stomach flu or food poisoning, require a temporary reduction in dietary fiber. Before using Metamucil to treat diarrhea, talk with your doctor.
Metamucil is a brand name of psyllium fiber used to treat constipation and diarrhea 4. Soluble fiber absorbs water in the digestive tract and swells, adding more bulk to your stool. Diarrhea consists of frequent, watery stools that lack bulk. The use of Metamucil may help provide the needed bulk to your stool, making the stool easier to pass and restoring regularity. PubMed Health states that using psyllium fiber may cause choking and lead to constipation if not taken with sufficient water 4.
Cause of Diarrhea
Metamucil & Bloating
The overuse of Metamucil can cause diarrhea. If you are already receiving a significant amount of fiber from your diet, using Metamucil may cause bouts of diarrhea. If you develop diarrhea from using this product, discontinue use and call your doctor. Diarrhea from psyllium husk may be a sign of a more serious condition, such as irritable bowel syndrome, Crohn’s disease or food intolerance 4.
- The overuse of Metamucil can cause diarrhea.
- If you are already receiving a significant amount of fiber from your diet, using Metamucil may cause bouts of diarrhea.
According to the product's label, you should use 1 tsp. in a single 8-oz. glass of water, three times a day. Depending on the severity of your diarrhea, your doctor may recommend more or less of the product. You may experience temporarily increased gastrointestinal discomfort when you first use the product because of the sudden increase of fiber in your diet.
- According to the product's label, you should use 1 tsp.
Wheat Dextrin & Fiber
Drugs.com warns that the use of psyllium husk fiber has been reported as causing allergic reactions 4. If you develop other symptoms alongside diarrhea, you may have an allergy to the supplement. Common allergy symptoms include:
- stomach pain
- facial swelling
- lip swelling
- trouble breathing
- shortness of breath
Call your doctor immediately if you develop one or more of these symptoms.
Metamucil & Bloating
Wheat Dextrin & Fiber
Psyllium & Upper Abdominal Pain
Benefiber & Bloating
Pros & Cons of Metamucil
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FiberCon Vs. Metamucil
- Metamucil: Sugar Free Original Directions
- University of Maryland Medical Center: Psyllium
- MedlinePlus: Fiber
- Drugs.com: Psyllium
- Bruma Jose M. Satiety effects of psyllium in healthy volunteers. Appetite. Volume 105, 1 October 2016, Pages 27-36. doi:10.1016/j.appet.2016.04.041
- Lever E, Cole J, Scott SM, Emery PW, Whelan K. Systematic review: the effect of prunes on gastrointestinal function. Aliment Pharmacol Ther. 2014;40(7):750-8. doi:10.1111/apt.12913
- de Bock M, Derraik JG, Brennan CM, et al. Psyllium supplementation in adolescents improves fat distribution & lipid profile: a randomized, participant-blinded, placebo-controlled, crossover trial. PLoS One. 2012;7(7):e41735. doi:10.1371/journal.pone.0041735
- Lambeau KV and Johnson W. McRorie, Jr. Fiber supplements and clinically proven health benefits: How to recognize and recommend an effective fiber therapy. J Am Assoc Nurse Pract. 2017 Apr; 29(4): 216–223. doi:10.1002/2327-6924.12447
- Moayyedi P, Quigley EM, Lacy BE, et al. The effect of fiber supplementation on irritable bowel syndrome: a systematic review and meta-analysis. Am J Gastroenterol. 2014;109(9):1367-74. doi:10.1038/ajg.2014.195
- Gibb RD, McRorie JW Jr, Russell DA, Hasselblad V, D'Alessio DA. Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus. Am J Clin Nutr. 2015 Dec;102(6):1604-14. doi:10.3945/ajcn.115.106989
- Proctor & Gamble. Metamucil.
- Food Information Council Foundation. Fiber Fact Sheet.
- El-Salhy Magdy, et al. Dietary fiber in irritable bowel syndrome (Review). Int J Mol Med. 2017 Sep; 40(3): 607–613. doi:10.3892/ijmm.2017.3072
- University of California San Francisco. Increasing Fiber Intake.
Diane Marks started her writing career in 2010 and has been in health care administration for more than 30 years. She holds a registered nurse license from Citizens General Hospital School of Nursing, a Bachelor of Arts in health care education from California University of Pennsylvania and a Master of Science in health administration from the University of Pittsburgh.