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), 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), 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
If you are suffering with 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.