Can Caffeine and Other Stimulants Irritate Your Bowels?


For more than 80% of Americans, grabbing a coffee right upon waking is simply the morning routine. However, if you experience digestive upsets such as diarrhea, your drink of choice may be to blame. Caffeine is considered both a drug and a food additive by the Food and Drug Administration. It’s also a stimulant that gets all your body’s systems going just a bit faster. This is why caffeine is a trigger for problems such as Irritable Bowel Syndrome (IBS) or anxiety. If you experience problems with your digestive system and intestines with caffeine, you can find out how to reduce those problems with these tips!

Why Do People Reach for Stimulants?

In today’s busy world, more and more people feel like they need a little boost to get them through the demands of the day. Coffee and other caffeinated beverages increase alertness and mental performance are are used daily by 90 percent of Americans with more than 50 percent of Americans having up to 300 milligrams of caffeine per day–it is America’s most popular drug.

What are Common Sources?

Caffeine is found naturally in many plants like coffee beans, tea leaves, and cocoa nuts. It is in a wide range of food products like coffee, tea, cola, and chocolate. It is artificially added to many other products, including a variety of energy drinks, gum, candies and more.

The Action of Caffeine

How Does Caffeine Work?

Ever wonder what exactly is happening, on a chemical level, when you ingest caffeine? Caffeine has similar properties to adenosine, a nucleoside that triggers drowsiness by reducing nerve cell activity. Caffeine binds to adenosine receptors, subduing the binding activity of adenosine molecules which then augments neuron firing in the brain.

Your pituitary gland responds to the increase in neuron firing and releases hormones that instigate the production of adrenaline (epinephrine) by your adrenal glands. Adrenaline nicknamed the “fight or flight” hormone, has the following effects on your body:

  • Constriction of blood vessels to slow blood flow (from wounds) and to increase blood flow to muscles
  • Increased blood pressure
  • Decreased blood flow to the stomach; a result, digestion can be slowed
  • Release of sugar from the liver into the bloodstream for extra energy
  • Tightening of muscles to jump into action
  • Pupil dilation
  • Increased breathing and heart rate

Is there a danger to putting your body into “fight or flight” mode every day? Yes. The body wasn’t designed to live at the level of tension/stress daily.

How Much Caffeine is Considered Safe?

According to the FDA, “for healthy adults FDA has cited 400 milligrams a day—that’s about four or five cups of coffee—as an amount not generally associated with dangerous, negative effects. FDA has not set a level for children, but the American Academy of Pediatrics discourages the consumption of caffeine and other stimulants by children and adolescents.”

After approximately one hour of consumption, caffeine reaches its peak, but remains in your body for up to six hours.

The Impact of Caffeine and Stimulants on your Digestive Tract

Regular coffee drinkers or caffeine users often report that the substances increase their bowel movements. Why is this?

Caffeine is a stimulant that augments your motility–or the contraction of the muscles that push/move contents in your gastrointestinal tract. (This is also called peristalsis.) Some use coffee/caffeine to help assist with bowel regulation because of this effect it has. But, caffeine is also a known diuretic and, if you aren’t careful about hydration, can cause dehydration. Why? Caffeine increases blood flow to the kidneys triggering an increase in urine production. Increased urine can lead to dehydration, which can cause constipation.

Another thing to consider, when coffee enters the stomach it has been shown to trigger a release of stomach contents into the small intestine before complete digestion has occurred.[5] Food that doesn’t complete the digestion process in the stomach can end up sitting and rotting in your gut. This fosters a toxic environment where bad bacteria can spread in the intestines, damage the intestinal wall, and leads to inflammation–an immune response to enzymes in the coffee, says the Global Healing Center.

Caffeine, especially in large doses, can cause the recipient to be jittery or anxious. These anxiety symptoms only make symptoms of IBS or IBD worse, according to research from the  University of Michigan.

Because of the acidity of caffeine, the amount of gastric secretions increases from caffeine exposure and use. This can cause irritation of the intestinal lining of the stomach causing stomach upset in some people.  High amounts of caffeine have been linked to ulcers and gastritis. Caffeine has also been shown to heighten symptoms if you have gastrointestinal problems like IBS and Crohn’s disease.

How About Sugar?

Energy drinks and soft drinks are a common source of caffeine but they also pack a heavy dose of sugar. Most eight-ounce servings of energy drinks on the market today have roughly 30 grams of sugar (seven teaspoons). Refined sugar in excess, especially taken all at one time, can lead to diarrhea in patients that suffer from IBS and IBD. These sugars aren’t absorbed correctly in the intestines and then the GI tract attempts to flush out the sugar by sending more water through the bowel.


Another popular stimulant on the market today is Guarana. Guarana has among the highest concentrations of caffeine in any plant. It may contain up to 3.6% to 5.8% caffeine by weight. (Coffee only has up to 2%.)

Experts have not studied guarana extensively. Research seems to indicate that  guarana is helpful for improving cognitive ability or mood.


Taurine plays an important role in the regulation of neuroendocrine functions and nutrition.  What does taurine do? According to, Taurine:

  • Supports proper hydration and electrolyte balance in your cells
  • Helps form bile salts, which play an important role in digestion
  • Regulates minerals like calcium within cells
  • Maintains the general function of the central nervous system and eyes
  • Helps with immune system health and antioxidant function

Taurine is called a “conditionally essential” amino acid; a healthy individual can manufacture the minimal amount required for these essential daily functions.

Research on the safety of taurine has suggested that up to 3,000 mg per day for an entire lifetime is still safe. According to the best available evidence, taurine has no negative side effects when used in the recommended amounts (11).

What you do need to watch out for is the combination of high doses of taurine with caffeine–a popular combination in energy drinks of today.

Call for a Consultation and Gut Health Evaluation

How healthy is your gut? Do you have questions about your current use of caffeine or other stimulants? Call 970-631-8286 and discover how healthy you are on a biochemical, molecular level. Learn strategies and tips to balance your body physically, mentally and emotionally so you can have what you need for total body wellness.