What is the cause of diarrhea & constipation?

If you've ever had a baby, you know how obvious it is when their digestive system isn't working quite right.

They eat, they poop. And when something doesn't agree with them, you usually know pretty quickly. Their little faces get red and scrunched up with gas or constipation, or you hear those unmistakable gurgling tummies that tell you diarrhea is on the way.

With babies, we tend to pay attention to these changes and try to figure out what caused them.

As adults, we're much more likely to ignore changes in our bowel habits.

One day of diarrhea? Probably nothing.

Skipping a day or two of bowel movements? You might just assume that's normal for you.

But your bowel movements can tell you a lot about how well your digestive system is functioning.

Your body is designed to move food through the digestive tract, absorb what it needs, and eliminate what it doesn't. Regular bowel movements are an important part of that process.

In functional medicine, bowel function is one of the clues that can help us understand what is happening throughout the digestive system.

How Often Should You Be Having a Bowel Movement?

One of the things I hear frequently from patients is:

"I've only gone to the bathroom two or three times a week for as long as I can remember, so I guess that's just normal for me."

I understand why someone would think that. If you've lived that way for years, it can be easy to assume that it must simply be your normal.

But from a functional-medicine perspective, less than one bowel movement per day is considered constipation and is not healthy bowel function.

A healthy digestive system should generally be eliminating waste regularly, with one to three bowel movements per day being a good functional goal for many people.

That doesn't mean you need to obsessively count every bowel movement or become a hypochondriac.

It simply means that your bowel habits are worth paying attention to.

If you are regularly going several days without a bowel movement, that is information your body is giving you.

And if you are having diarrhea regularly, that is information too.

What Causes Constipation and Diarrhea?

There isn't necessarily one cause.

Constipation occurs when stool moves too slowly through the digestive tract, allowing too much water to be reabsorbed. Diarrhea can occur when stool moves too quickly, when too little water is absorbed, or when the digestive tract is responding to an infection, irritation, inflammation, or another underlying problem.

In either case, the symptom is telling us that something about normal bowel function has been disrupted.

Some of the most common contributing factors I look for include:

1. Diet and Hydration

What you eat can have a major impact on bowel function.

A diet high in processed foods and added sugar, along with inadequate fiber, inadequate water intake, or excessive intake of certain beverages, can interfere with normal digestion and elimination.

For some people, simply improving food quality, hydration, and meal patterns can make a significant difference.

But diet is not always the whole story.

If you've already improved your diet and are still experiencing chronic constipation or diarrhea, it's worth asking what else could be contributing.

2. Infection or Imbalance in the Digestive Tract

Your digestive tract contains a complex community of microorganisms that plays an important role in digestion and overall gastrointestinal function.

An acute gastrointestinal infection can obviously cause diarrhea.

But changes in the digestive microbiome can also contribute to ongoing digestive symptoms.

This can happen for a variety of reasons, including repeated antibiotic use, illness, dietary patterns, or other changes within the digestive environment.

If you've noticed that your digestion has been different since taking antibiotics, having a gastrointestinal infection, or experiencing another significant health event, that history can be an important clue.

Depending on the symptoms and history, functional laboratory testing may help identify problems that aren't obvious from symptoms alone.

3. Food Allergies and Sensitivities

Food reactions can also affect bowel function.

Some people notice that a particular food causes almost immediate symptoms. Others may have a much more delayed response.

Food sensitivity reactions do not always occur immediately after eating the food.

A reaction may occur hours or even days later, making it extremely difficult to identify the offending food simply by keeping track of what you ate immediately before your symptoms appeared.

This is one reason food-sensitivity testing can be particularly helpful in some patients.

Instead of guessing which food might be causing a problem, testing can provide additional information that helps us determine whether certain foods may be contributing to digestive symptoms.

If you suspect that food is playing a role in your constipation, diarrhea, bloating, or other digestive symptoms, food sensitivity evaluation may be worth considering.

4. Digestive Support

Proper digestion requires more than simply putting food into your mouth.

Your digestive system relies on stomach acid, digestive enzymes, bile, pancreatic function, intestinal motility, and coordinated nervous system signaling to break down food and move it through the digestive tract.

If one or more parts of that process isn't functioning properly, you may experience changes in bowel function.

For example, impaired digestion can contribute to symptoms such as:

• Bloating

• Gas

• Indigestion

• Feeling overly full after meals

• Changes in stool consistency

• Constipation

• Diarrhea

This is one reason I don't believe in simply throwing another supplement at every digestive problem.

The right digestive support depends on why the digestive system isn't functioning properly in the first place.

5. Medications

Medications can also have a significant effect on bowel function.

Some medications can contribute to constipation, while others may cause diarrhea. Certain medications can also alter gastrointestinal motility or affect the digestive environment in other ways.

If your bowel habits changed after starting a medication, don't assume it's unrelated.

And if you're taking a prescription medication, don't stop it on your own. Instead, talk with the prescribing physician about whether it could be contributing to your symptoms and whether an adjustment is appropriate.

6. Changes After Surgery

Certain abdominal surgeries can also change digestion and bowel function.

Gallbladder removal, bowel surgery, appendectomy, and other procedures can alter the way the digestive system functions.

That doesn't necessarily mean you are destined to have digestive problems forever.

There may still be ways to support digestion and normal bowel function based on what has changed and what your body needs now.

What About IBS, Crohn's Disease, and Ulcerative Colitis?

You may notice that I haven't listed IBS, Crohn's disease, or ulcerative colitis as causes above.

That's intentional.

These diagnoses are important, and they can absolutely be associated with constipation, diarrhea, abdominal pain, inflammation, and other digestive symptoms.

But a diagnosis doesn't necessarily tell us everything that is contributing to an individual person's symptoms.

For example, inflammatory bowel disease (IBD), which includes conditions such as Crohn's disease and ulcerative colitis, are complex inflammatory conditions with multiple factors involved, and conventional medical treatment is often an important part of managing them.

At the same time, research continues to demonstrate that factors such as the gut microbiome, diet, intestinal barrier function, immune regulation, genetics, and environmental influences can all play roles in IBD.

That means there can be value in asking:

What factors may be contributing to this person's inflammation and symptoms?

In my practice, I have worked with many patients with IBD who have been able to experience significant improvement in their symptoms by identifying and addressing contributing factors through a more comprehensive evaluation.

That does not mean that everyone with IBD has the same underlying factors, or that functional care replaces appropriate medical treatment.

It means that the diagnosis itself may not be the end of the investigation.

The same principle applies to IBS.

Being told you have irritable bowel syndrome can explain the pattern of symptoms you're experiencing, but it doesn't necessarily explain why your digestive system has become irritated or dysfunctional.

Looking more closely at diet, food reactions, digestive function, microbiome changes, nutrient status, stress, medications, and other factors can sometimes provide useful information about what may be contributing to the symptoms.

Why Paying Attention to Your Bowel Habits Matters

Let's go back to that baby example.

Imagine your baby suddenly develops diarrhea.

You start looking for an explanation.

Maybe Mom ate something different.

Maybe there was a change in formula.

Maybe the baby picked up a stomach bug.

Maybe a particular food didn't agree with them.

You don't simply decide that diarrhea is their new normal.

You pay attention because the change tells you something.

As adults, we tend to lose that awareness.

We get busy.

We eat differently.

We take antibiotics.

We start new medications.

We experience more stress.

We notice that we're suddenly bloated or constipated, but we don't think much about it.

Then six months or a year later, we're having digestive symptoms several times a week and can't remember when they actually started.

Sometimes the earliest signs of digestive dysfunction are subtle.

Maybe you're no longer having a bowel movement every day.

Maybe you suddenly need coffee to get things moving.

Maybe you are more bloated after meals than you used to be.

Maybe certain foods don't seem to agree with you anymore.

Maybe your stool consistency has gradually changed.

These changes don't necessarily mean that something serious is wrong.

But they are worth noticing.

What Can You Do If You're Having Constipation or Diarrhea?

There are two important approaches.

First, Look at the Pattern

If you're having an occasional episode of diarrhea or constipation, think about what was happening around the time it occurred.

Ask yourself:

• What have I been eating?

• Have I been drinking enough water?

• Have I started or changed a medication?

• Have I recently taken antibiotics?

• Have I been under unusual stress?

• Has my digestion been changing gradually?

• Are there foods that seem to trigger symptoms?

• Have I noticed bloating, gas, indigestion, or other digestive changes?

You may not immediately find the answer.

That's okay.

The goal isn't to diagnose yourself.

The goal is to start recognizing patterns.

Second, If It's Chronic, Find Out Why

If constipation or diarrhea has become a regular part of your life, simply treating the symptom may not be enough.

You can take something to make yourself go.

You can take something to stop diarrhea.

You can add another probiotic.

You can eliminate another food.

But if you don't know why the problem is happening, you may simply be managing the symptom without addressing the underlying contributor.

This is where a more comprehensive evaluation can be helpful.

Depending on your symptoms and history, that may involve looking at digestive function, food reactions, nutritional status, microbiome-related concerns, medication use, inflammation, and other factors that could be affecting your bowel function.

Functional laboratory testing may also provide additional information when appropriate.

At Whole Health & Wellness, we use your symptoms, health history, examination findings, and laboratory information together rather than assuming that every person with constipation or diarrhea needs the same treatment.

The Goal Isn't Just to Make You Go

Constipation and diarrhea are symptoms.

They are also information.

Your bowel movements can give us clues about how well your digestive system is functioning and whether something has changed.

If you're having chronic digestive problems, the goal shouldn't simply be to find something that forces your bowels to move or stops them from moving.

The goal is to understand why your bowel function has changed in the first place.

That may mean looking at food, digestion, the microbiome, medications, food sensitivities, inflammation, or other contributing factors.

And sometimes there is more than one factor involved.

That's why individualized evaluation matters.

When Should You Seek Medical Care?

Occasional changes in bowel function are common, but persistent or severe symptoms should not be ignored.

Talk with a healthcare professional if you have ongoing constipation or diarrhea, blood in your stool, black or tarry stools, unexplained weight loss, severe or persistent abdominal pain, fever, persistent vomiting, or other symptoms that concern you.

If you have been diagnosed with Crohn's disease, ulcerative colitis, or another gastrointestinal condition, work with your medical team to manage the condition appropriately while exploring additional supportive approaches when appropriate.

How We Can Help

At Whole Health & Wellness, we look beyond the bowel movement itself.

We want to understand what is happening throughout your digestive system and what factors may be contributing to your symptoms.

Depending on your individual situation, your evaluation may include functional laboratory testing, nutritional assessment, evaluation of food sensitivities, and a closer look at digestive function and other factors that may be affecting your health.

Your care plan may include nutrition and lifestyle recommendations, targeted nutritional support, and other individualized integrative approaches.

The goal isn't to give everyone the same diet or the same handful of supplements.

It's to understand what your body is telling us and determine what it needs.

If you're dealing with chronic constipation, diarrhea, bloating, food reactions, or other digestive problems, you don't have to simply accept them as "normal for you."

There may be more to the story.

Start Your Personalized Care Plan

If you're ready to better understand what's contributing to your digestive symptoms and take a more complete, natural approach to your health, we're here to help.

About the Author

Dr. Caroline Ricker, DC, DABCI, MTAA, is the founder of Whole Health & Wellness in St. Louis. Her practice combines functional medicine, clinical nutrition, functional laboratory testing, chiropractic care, acupuncture, and other integrative approaches for patients with chronic and recurring health concerns.

Learn more about Dr. Caroline Ricker and Whole Health & Wellness