Bowel Transit Time Tests and Tips

Are you wondering how long it takes your body to empty its bowels? Do you wonder why you feel bloated after eating certain foods? Or maybe you’ve had trouble with constipation and wondered if it was caused by diet?

In this article, I’ll share tests for measuring bowel transit time and tips to improve transit times.

What is the Bowel Transit Time?

Bowel transit time refers to the amount of time (in hours) it takes for a particular meal or food to travel from the mouth, to the digestive tract and through it, and for waste products to be eliminated through a bowel movement.

A healthy person should experience a bowel transit time of 8 to 14 hours. People should have two to three bowel movements per day.

Transit times can vary greatly from person to person due to age, dietary habits, climate, exercise habits, immobility, medications and so on. Due to the many different factors involved, exact bowel transit times for the general public cannot be determined.

Fiber-rich diets, good physical fitness, and not taking any medications with constipating side effects are most likely to result in a healthy transit time.

Why Measure Bowel Transit Time

A bowel transit time test is performed by health care practitioners to understand and evaluate abnormal bowel movements in patients. It is not a common test because of the many variables that can influence test results.

If you want to perform home tests, you should consider doing them more than once to find an average transit time. Your personal bowel transit time may vary due to food intake, menstrual cycles, changes in exercise, seasonal changes, or changes in medication, so results may vary a little with each test. 

Best Bowel Transit Time Tests

There are several ways of measuring your transit time. Each test requires that you ingest something that can be tracked as it travels through your digestive system, or can be seen as it exits your body. 

1. Bowel Transit Time Home Test

The simplest test you can do at home involves foods that don’t digest easily, such as kernel corn or beets. First, avoid eating that food for a week or two before starting the test.

Make note of the time you eat the chosen food and then start monitoring your stools for the presence of the food and to find your transit time range.

The time between when you first ingest your food to the time of your first stool with the undigested food is the front end of the time range. The back end of the range is when the food stops showing up in the stool. For example, the transit time range could be 8 to 14 hours. 

2. Bowel Transit Time Dye Test

Another test option is the dye test method, which can also be done at home. It requires that you swallow a capsule that contains an indigestible dye substance. Mark the time when you swallow the dye capsule and look for the dye to start appearing in your stool.

Your bowel transit time range is the time between when you take the capsule, and when the dye appears in your stool and disappears from your stool (e.g., range of 8-14 hours).

3. Bowel Transit Time Pellet Test

The pellet test involves x-rays and therefore requires medical assistance. First, you will swallow small indigestible pellets and then take x-rays of your abdomen.

The pellets will appear as white spots or circles on an x-ray. This process can take several days and requires taking additional x-rays during the testing period.

The doctor will analyze the amount and location of the pellets to measure bowel transit time. With doctors and additional x-rays needed, it’s inconvenient and can be inconsistent. 

Due to the inconvenience and inconsistency of this test method, pellet testing is mostly reserved for patients suffering from severe constipation. That can help determine if the constipation is related to slow transit through the large intestine or an evacuation disorder (where they pass through at a normal rate, but are not expelled from the rectum as expected). 

Tips to Improve Bowel Transit Time

If you’re experiencing any kind of digestive discomfort, like constipation, full­ness, or bloating, then you should try to improve transit time.

There are several ways to improve your bowel transit times. Here they are listed in order from most important to least important, but all are vital for becoming a truly healthy person.

  • Increase your daily fiber intake to 25-30 grams daily.
  • Start exercising.
  • Drink ½ of your body weight in ounces of purified water daily.
  • Listen to your body for bowel movement signals and don’t delay the urge to defecate.
  • Eliminate regular use of chemical laxatives. They reduce colon muscle tone and are counterproductive in the long run.
  • Eat meals on a regular schedule.
  • Stop eating before you are full, because your brain signals the feeling of fullness 10 minutes after you are actually full.
  • Reduce portion sizes to the size of your fist.

Bowel Transit Time Final Thoughts

A good bowel transit time is an important part of a healthy person’s lifestyle. Slow times increase the risk of anal fissures, hemorrhoids, constipation, upper abdomen bloating, gas, and abdominal discomfort or pain.

A healthy transit time (8-14 hours) reduces bloating, gas, indigestion, fullness, constipation and abdominal pain.  It can help reduce anorectal disorders as well.

Bowel transit time tests can be performed in the comfort of your own home. Dietary modifications and exercise can improve bowel transit without major life altering changes The difficulties with any attempts to improve bowel transit outweigh the risks of doing nothing and developing serious diseases.

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Julie C. Guider MyGoodGut

Medically reviewed by Julie Guider, M.D.

Dr. Julie Guider earned her medical degree from Louisiana State University School of Medicine. She completed residency in internal medicine at the University of Virginia. She completed her general gastroenterology and advanced endoscopy fellowships at University of Texas-Houston. She is a member of several national GI societies including the AGA, ACG, and ASGE as well as state and local medical societies.