What Causes Constipation?

Why Can’t I Poop?

What Causes Constipation


First of all, the definition for constipation is difficulty emptying the large bowel.  There are a number of causes for constipation. The most common reasons usually have to do with what you eat, and your overall pooping habits.  There are also medical possibilities so, as always with your body, when in doubt check with a doctor.

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Of course, you may not have constipation at all.  Some people think they’re constipated if they hear that someone else poops more often than they do.  To learn more about how often you should poop, check this link on pooping frequency.

Constipation Symptoms

The primary symptoms of constipation include:

  • Passing smaller amounts of stool than usual when pooping
  • Pooping less than usual
  • Straining when pooping
  • Hard, dry, or lumpy stool
  • Less common symptoms of constipation can include:
  • A bloated, overly-full feeling
  • Cramping and other pain in the abdominal area
  • Nausea
  • Loss of appetite

Effects of Constipation

Constipation itself is usually an inconvenience and, like poop, eventually passes on its own.  However, if constipation gets too severe, or lasts too long, it can lead to other problems.

Issues that can result from severe or prolonged constipation include:

Symptomatic hemorrhoids, also called piles, which are inflamed and/or swollen blood vessels in the anus

Anal fissures which are tiny tears in the tissue on or around the anus

Rectal bleeding, most often from hemorrhoids or anal fissures

Impaction, when dry stool collects in the rectum and/or anus, becoming compacted, and creating a physical obstruction in your bowels.

There are also “non-physical” effects, such as restricting your activities because of constipation pain or embarrassment

What Causes Constipation?


As mentioned earlier, diet tends to be the biggest factor for anything having to do with pooping, including constipation.  When talking specifically about constipation, fiber is probably the biggest dietary factor.

People who regularly include high fiber sources in their meals are far less likely to end up constipated.  Fiber prevents constipation by keeping your bowel movements regular. Fiber also absorbs a lot of moisture — assuming you’re drinking enough fluids — which makes it easier for stool to pass through your bowels.

High fiber foods include whole grains, nuts, vegetables, fruit, chickpeas, lentils, and other legumes.  Low fiber meals tend to be those high in fat, such as cheese, fast foods, processed snacks (junk food) and many prepared foods and meals.  Meat is also another low-fiber culprit as is any highly-processed food, such as white bread.

Physical Activity

Or, more accurately, a LACK of physical activity (or very little) can lead to little or no bowel activity, aka constipation.  Science can’t tell you exactly why, but the evidence is pretty solid that people who move around more, poop better and have to deal with constipation a lot less often.  The dominant theory is that the movement physically stimulates the bowel region, kickstarting digestion, absorption, and elimination.

There is also a lot of evidence and examples of sedate people, and those confined to a bed or chair for a long period of time, being at greater risk of constipation.


Before we go any further, NEVER stop doctor prescribed or recommended medication to try and solve a constipation problem without consulting a doctor first.  Constipation as a side effect can definitely be a problem, but stopping any kind of treatment is very likely much worse.

There are common prescribed, over-the-counter, and off the shelf medications and supplements that can result in constipation.

  • Opiods. That includes oxycodone (OxyContin), codeine (often combined with acetaminophen as in Tylenol #3), and hydromorphone (Dilaudid).
  • Some anticonvulsants, including carbamazepine (Tegretol), and phenytoin (Dilantin)
  • Tricyclic antidepressants, including imipramine (Tofranil) and amitriptyline (Elavil)
  • Calcium channel blockers including nifedipine (Procardia) and diltiazem (Cardizem)
  • Antacids containing calcium.
  • Diuretics.  Many medications and supplements cause the body to eliminate fluids at a greater than normal rate.  Examples include furosemide (Lasix) and hydrochlorothiazide (Hydrodiuril). Contrary to popular belief, the diuretic effect of coffee is not an issue since the amount taken in exceeds the small amount that is lost due to the diuretic effect.
  • Iron supplements.  Most often prescribed for iron deficiency/anemia, iron supplements can also change the color and texture or your poop.  Check out what color should my poop be, on this website.
  • Irritable Bowel Syndrome (IBS)
  • IBS, or irritable bowel syndrome can certainly result in constipation.  However it also has other symptoms including, ironically, diarrhea. If you are frequently alternating between constipation and diarrhea, IBS may be the cause.  A doctor’s examination and tests are the only sure way to diagnose it though.

Getting Old

As if aging didn’t have enough problems associated with it.  The chances of you being constipated increase with every year.  The exact cause of constipation with aging hasn’t been determined, but up to 40% of the elderly living “on their own” suffer from constipation.  Surprisingly, those in care facilities (where you’d expect someone would be monitoring this) can see rates of 60% dealing with constipation.

Again, not proven, but it’s likely that as people grow older they slow down, and it’s been shown that less activity can mean more constipation.  As people age, their diets and medications change as well, and these will also have an effect.  

Life changes

Change your routine and, possibly, change your pooping — sometimes diarrhea, often constipation.  A change in your routine can be something as small as suddenly starting to sleep in, resulting in skipped breakfasts, to something as significant as vacationing in another country — disrupting your regular diet, changes to your body clock (with any major east or west location changes), unfamiliar surroundings making it uncomfortable to poop, and possibly local destination illnesses.


Yup… the usual cure for constipation can also be a cause.  Laxative overuse often starts with a concern that the person involved isn’t pooping the right amount and/or at the right frequency.  As discussed in How Often Should I Poop, on this website, comparing your bowel movement to anyone else is a bad idea.

Laxatives can and do aid bowel movements but, depending on the type of laxative, your body can get used to, and build up a resistance to their effects.  It’s kind of like the pooping version of a caffeine addiction. After awhile, one cup doesn’t do it, so you have two… then three… then thirty and, if you stop or try to reduce the amount, you crash.  Your bowels will treat some laxatives the same way — requiring higher and/or more frequent doses to get the same effect and, if you stop suddenly, risking a constipation crash.

More bad news.  Overuse of laxatives can also cause dehydration, electrolyte imbalances and, in extreme cases, organ failure.

If you’re using laxatives on anything more than a rare occasion, it should only be at a doctor’s recommendation.  If not, see your doctor about reducing your laxative use.

Holding it in

We touched on this briefly above when mentioning unfamiliar bathrooms while traveling.  If you hold back a bowel movement — because you don’t like a different toilet, you’re in a meeting, or whatever — the urge often goes away.  However, too long a delay, or habitual delaying will leave the stool parked in the digestive system, drying out, getting hard, and increasing the risk of fecal impaction mentioned above.


Your digestive system requires water/liquid to operate.  Liquid keeps the stool soft and pliable. While some people will say that certain liquids/drinks will increase constipation, there is very little scientific proof of this.  A great example is coffee. Some people say it makes them constipated, other people say it makes them poop. The best thing to do is drink whenever you’re thirsty — your body is pretty reliable at reminding you how much fluid you need.  

Medical issues

It needs to be noted that consistent constipation could be the symptom of a far more serious problem.  That’s why, if there’s any doubt, check it out (with a doctor). Because the list is too extensive and should not be self-diagnosed, we’re simply listing some serious constipation causes purely for reference sake.

Serious medical conditions that could have constipation as a symptom include:

  • Hernias
  • Diverticulitis
  • Tumors
  • Scar tissue from injuries or surgery
  • Colorectal stricture
  • Inflammatory bowel disease (briefly covered above)
  • Parkinson’s disease
  • Spinal cord injuries
  • Multiple sclerosis
  • Diabetes
  • Hypercalcemia
  • Hypothyroidism
  • Uremia
  • Celiac disease
  • Chemotherapy

Constipation in newborns

If a newborn doesn’t pass their first solid stool, called meconium, within 48 hours after being born, they might be suffering from something called Hirschsprung’s disease.  This is caused when specific nerve cells are absent from part of the large intestine. The lack of these nerves prevents stools from moving into that area of the colon and, obviously, stool that isn’t moving is constipation.  Thankfully, the long-term outlook for babies born this way is very good.  

Constipation in Infants

Other than the obvious not pooping, other signs of constipation in an infant can be a “hard” or distended abdomen, an unusual loss or reduction of appetite, increased irritability, or an unusual lack of energy.

Breastfed infants rarely experience constipation, and it’s possible for a breastfed baby to be quite healthy and not pass stool for up to a week.  As always though, if you have any concerns about constipation in a baby, or you notice other signs of abdominal discomfort, consult a doctor.

Common causes of minor constipation in infants can include initiating formula feeding.  This often is just a lack of water. Do not water down the formula itself, but do encourage the baby to drink more water between feedings.

Constipation can also occur when the baby is being weaned and/or introduced to solids.  This can often be remedied by including high-fiber fruits and encouraging more water consumption.

Potty training can also cause constipation for a couple of reasons.  One, you’re changing the “routine” for emptying bowels and, two, the child may feel some stress during the process.  Other causes of stress can also be a factor, such as starting at daycare.  

While we’re discussing infant constipation let’s switch to the other side of the equation — being constipated while pregnant.

One study indicated that about 40% of women will be constipated at some point during pregnancy — so you’re not alone!  So what casues constipation in pregnant women?  Since you’re pregnant for nine months, there’s a chance that something “norma” is affecting your bowel movements — just like non-pregnant people.  However, specific causes of constipation during pregnancy can be hormonal changes, the physical rearrangement of your digestive system as the baby grows, changes in your eating or activity level, and supplements (including iron) can have side effects that include constipation.

Looking for a constipation solution?  Click here.


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