Constipation: The Thyroid Symptom No One Wants to Talk About

Doctor having discussion with male patient
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Constipation is a problem that can be particularly troublesome for people with hypothyroidism -- an underactive thyroid. Hypothyroidism slows down many of the body's systems, including digestion and elimination. And unfortunately, some people can end up being chronically constipated as a result.

Defining Constipation

First, let's define what is technically meant by constipation. You may think you are supposed to have one bowel movement each day.

But actually, less than 50 percent of people do. People may have bowel movements anywhere from four to 20 times per week.

Constipation is typically defined by physicians as having three bowel movements or less in a week. Other clinical symptoms doctors consider are the need to strain during bowel movements, lumpy or hard stools, and a sensation that bowel movements are incomplete or blocked in some way.

As food moves through the colon, also known as the large intestine, water from food is absorbed. After the water is absorbed, waste product (stool) is formed. Muscles in the colon contract to move the stool through the intestine toward the rectum. Water continues to be absorbed so that the stool becomes more solid before elimination.

Constipation occurs because too much water is absorbed from the food, or the colon isn't contracting frequently or strongly enough. The stool moves too slowly as a result.

Sluggish, slower, or weaker colon contractions can be characteristic of hypothyroidism and are contributing factors to chronic constipation problems in people with hypothyroidism.

Symptoms of Constipation

In addition to the reduced number of bowel movements per week (three or less), the stool is usually hard and dry.

Often, it can be painful to pass stool and doing so requires straining or additional discomfort. In addition, people with constipation may feel some abdominal bloating or experience gas. Constipation can also make you feel tired, irritable, or blue.

Causes of Constipation

In addition to the general intestinal slowdown and fluid accumulation that are characteristic of hypothyroidism, there are other causes of constipation:

  • Eating too much meat, cheese, and low-fiber foods, and not enough fiber (like whole grains)
  • Not drinking enough liquids/dehydration
  • Physical inactivity (especially in the elderly)
  • Medications, including pain medications (especially narcotics such as codeine and oxycodone prescribed after surgery), antacids that contain aluminum and or calcium, blood pressure medications, antidepressants, anticonvulsants, diuretics, drugs for Parkinson's disease, and antispasmodics.
  • Supplements, especially those containing iron
  • Overuse of laxatives -- self-medication with over-the-counter laxative products that have become habit-forming
  • Ignoring the urge to have a bowel movement
  • Specific diseases or conditions, such as irritable bowel syndrome, neurological disorders (stroke, Parkinson's, MS), metabolic problems such as diabetes, and autoimmune diseases such as amyloidosis, lupus, and scleroderma
  • Problems with the colon and rectum, including intestinal obstructions, scar tissue, adhesions, or other structural issues
  • Other issues, including pregnancy and traveling

Seeing Your Doctor

If you are suffering from chronic constipation and have not had your thyroid evaluated, see your doctor for a comprehensive thyroid evaluation--an essential part of your doctor's overall assessment. The doctor may also run blood tests to rule out other conditions that can cause constipation.

Keep in mind that you should see your doctor right away if your constipation has come on very rapidly with no reason. Also, see your physician if constipation is accompanied by symptoms such as bleeding from the rectum, rectal bleeding, abdominal pain, cramps, nausea, vomiting, or noticeable weight loss.

In general, however, most doctors will start with a medical history and physical exam. The doctor will want to know about the frequency of your bowel movements, the characteristics of your stool, your eating and drinking habits, medications you take, and your level of physical activity.

Typically, your doctor will also do a physical exam, including an evaluation of your rectal area.

Especially for Thyroid Patients

Be absolutely sure that your thyroid treatment is optimized, as insufficient treatment may contribute to constipation problems. To help, read My TSH Test Results Are Normal, But I Still Have Symptoms.


Increase Your Fiber Intake With Food

Dietary changes, including getting 25 to 35 grams of fiber a day, are a first-line treatment for constipation, especially for thyroid patients. Getting to this level can be done in several ways. Ideally, you'll replace low-fiber foods with high-fiber foods.

High-fiber foods include many fruits and vegetables, whole grain breads and cereals, and beans. Some of the highest fiber foods include fruits like berries, greens, and whole grains.

For more ideas on how to incorporate more high-fiber foods into your diet, see my High-Fiber Fruits, Vegetables and Foods list for more ideas.

Important Note for Thyroid Patients:

Some high-fiber foods are also goitrogenic, meaning that they promote thyroid enlargement and can potentially cause or aggravate hypothyroidism. Typically, the risk is highest when these foods are consumed raw, regularly, and in substantial quantity. Cooking eliminates most goitrogenic properties.

Increase Your Fiber Intake With Fiber Supplements

Since it's difficult to get this amount of fiber daily, you may also want to consider a fiber supplement. These can include natural psyllium husks or flax seeds stirred into your juice, or a packaged fiber supplement. Fiber supplements are considered laxatives and are called "bulk-forming laxatives." They are generally safe, especially when compared to laxative medications.

These laxatives, also known as natural or "vegetable" laxatives, are fiber supplements taken with sufficient water. They absorb the water in the intestine and make the stool softer. Brand names include Metamucil, Fiberall, and Citrucel, among others. These agents must be taken with water or they can cause obstruction.

Many people also report no relief after taking bulking agents and suffer from a worsening in bloating and abdominal pain.

Fiber laxatives contain various types of fiber, ranging from psyllium to methycellulose. At your local grocery or drugstore, you can always get the traditional supplements, such as Metamucil. I happen to really like the newer fiber supplement BeneFiber, which is a tasteless powder that dissolves completely in liquid and doesn't get thick. You can add it to food or drinks, even coffee. You can also find fiber in other forms, including chewable tablets and capsules you can swallow.

Some people like a very high-fiber supplement that provides both soluble and insoluble fiber in high doses. One I like and regularly use myself is Dr. Levine's formula. This powder produces a quickly thickened shake-like drink that packs 15 or more grams of fiber per serving.

Important Note for Thyroid Patients:

Increasing the fiber in your diet can affect your absorption of thyroid hormone. Be sure to take your thyroid medication at least two to three hours apart from fiber-rich foods and supplements if possible.

You should have your thyroid function retested about eight weeks after you start a fiber-rich diet or supplements--you may need an increased drug dosage to account for absorption changes due to the fiber.

Fiber supplements can also interfere with other medications besides those taken for thyroid disease. If you are taking any medication, be sure to discuss this with your health practitioner.

Lifestyle Changes

Make sure that you are getting enough liquid. This means at least 64 ounces a day (not including caffeinated beverages) and even more if you are overweight. Daily exercise is essential. Even a short walk is helpful.

Make sure that you have enough time, and privacy, for a comfortable bowel movement. And don't ignore, put off or delay the urge for a bowel movement.

Traditional Osteopathic Treatment

Osteopathic manipulation by a trained doctor of osteopathic medicine(DO) can be a painless, effective, and medication-free treatment for constipation for some people. For more information on osteopathic physicians and how to find one, read my article.


If you have tried diet and lifestyle changes and are still suffering from chronic constipation, you'll want to talk to your doctor about laxatives. Because chronic constipation should be evaluated by your physician, and most laxatives can be habit-forming, it's best not to self-treat with laxatives. Instead, talk to your practitioner for guidance.

Laxatives come in various forms, including pills, capsules, liquids, powder, gum, and "candy" form.

Some of the most common laxatives include:

  • The almighty prune -- Prunes and prune juice are considered reliable, food-based laxatives, with little risk and few side effects
  • Stimulant laxatives, which cause the intestines to contract. Some of these include Correctol, Dulcolax, and Senokot.
  • Stool softeners, which help loosen stool. Brand names include Colace and Surfak.
  • Lubricants, which help the stool move more easily. These are usually administered internally, as a suppository, or via enema. These include mineral oil, Fleet enemas, and Zymenol.
  • Saline laxatives, which attract water into the colon, such as Milk of Magnesia.
  • Serotonin agonists, which help the intestines work better if an imbalance in serotonin (a neurotransmitter) is causing the problem.

There are other specialized prescription laxatives that you can discuss with your doctor. Most laxatives are habit-forming, however, and prolonged use of even over-the-counter laxatives can cause a variety of problems, including dependence and electrolyte imbalances.

Alternative Approaches

A number of natural treatments may be helpful:

Probiotic Therapy -- Use of probiotic supplements (such as lactobacillus acidophilus and bifidobacterium) may help with digestive problems and chronic constipation. An excellent probiotic that I use is Enzymatic Therapies' brand Acidophilus Pearls.

Triphala -- Triphala is a popular Ayurvedic remedy in the natural Indian tradition. This herbal laxative formulation can be very effective and gentler than other laxatives.

I particularly like the Planetary Formulas Triphala formula developed by Dr. Michael Tierra. (See an article by Dr. Tierra.)

Herbs -- Herbal teas, tinctures, and supplements can have mild or strong laxative properties. Some of the herbs and natural remedies used for laxative purposes include rhubarb, cascara sagrada, dandelion root, and aloe vera juice.

(Note: Do keep in mind that some herbal treatments have the same risks as over-the-counter and prescription laxatives and should not be self-prescribed for more than occasional use.)

Yoga -- Some people find stretching and gentle exercise that works the abdominal area (such as yoga or Pilates) especially helpful. Check out this series of yoga postures to help food transit at

Hydrotherapy -- Some alternative practitioners recommend regular sitz baths or hot baths to help relax the intestinal area and encourage regular elimination.

Homeopathy -- Homeopathic practitioners recommend Nux Vomica 6c and Sepia 6c for constipation.

Touch Therapy -- Various forms of massage and touch therapy, including lymphatic massage, may help with chronic constipation.

Biofeedback/Hypnotherapy -- Some people have found biofeedback and/or medical hypnotherapy helpful in retraining muscles and relaxation.

Next Steps

Occasionally, chronic constipation can lead to additional complications. The most common are hemorrhoids, rectal prolapse, or fecal impaction. Ideally, your doctor's treatment should help avoid these sorts of serious complications.

If diet, exercise, lifestyle changes, and over-the-counter or prescription medications--and proper thyroid treatment for thyroid patients--are not resolving chronic constipation, then consultation with a gastroenterologist for more extensive testing will likely be recommended.

Tests may include:

  • Colorectal transit study, to monitor how well food moves through the colon
  • Anorectal function tests, to evaluate abnormal functioning of the anal sphincter or rectal muscles and area
  • Defecography--an X-ray that can help identify abnormalities
  • Barium enema X-ray to identify obstructions or nerve problems in the rectum, colon, and lower part of the small intestine
  • Colonoscopy or sigmoidoscopy, which involves examining the inside of the intestines using a long flexible tube

More aggressive treatments for severe, unresponsive constipation may include surgical treatment or more complex regimens of drug treatment.


National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

Mary ShomonThyroid Guide since 1997, is a nationally-known patient advocate and best-selling author of 10 books on health, including "The Thyroid Diet: Manage Your Metabolism for Lasting Weight Loss," "Living Well With Hypothyroidism: What Your Doctor Doesn't Tell You...That You Need to Know," "Living Well With Graves' Disease and Hyperthyroidism," "Living Well With Autoimmune Disease," "Living Well With Chronic Fatigue Syndrome and Fibromyalgia," and the "Thyroid Guide to Fertility, Pregnancy and Breastfeeding Success." Click here for more information on Mary Shomon.