Can Constipation Cause Nausea? 9 Safe Relief Steps

Can constipation cause nausea? Yes. Constipation can occur with nausea, especially when stool moves slowly, the abdomen becomes bloated or distended, appetite falls, or constipation becomes severe. But nausea can also have another cause, so repeated vomiting, severe pain, or inability to pass gas should not be blamed on ordinary constipation.

The useful question is not only whether constipation can make you nauseated.

It is whether your symptom pattern still looks like uncomplicated constipation or whether it is moving into something that needs medical care.

Medical note: This article is for general information and education. It does not replace medical advice, diagnosis, or treatment.

I am not a dermatologist or a doctor, and this content does not replace professional medical advice. What I share comes from real life experience, extensive research, and consultation with healthcare providers. Always consult qualified medical professionals for diagnosis and treatment of any health condition.

Clinical review status: This article has not been independently medically reviewed by a physician, gastroenterologist, pharmacist, or registered dietitian.

NIDDK specifically advises prompt medical assessment when constipation occurs with vomiting, constant abdominal pain, inability to pass gas, fever, bleeding, or unexplained weight loss.

Why Can Constipation Cause Nausea?

Constipation changes how material moves through the digestive tract.

When stool moves slowly through the colon, you can develop abdominal bloating, pressure, fullness, cramping, and reduced appetite. Cleveland Clinic lists feeling bloated and nauseated among constipation symptoms.

Severe constipation can create even more pressure.

If a large hard stool becomes stuck in the rectum, you may develop a fecal impaction. Cleveland Clinic lists nausea among its severe symptoms.

There is also a broader connection between the upper and lower digestive tract.

Your digestive system communicates through muscles, nerves, hormones, and the gut brain system. Slow movement in one part of the gastrointestinal tract can be associated with symptoms elsewhere.

That is a better explanation than saying constipation causes “toxins to build up.”

How Do You Know if You Are Actually Constipated?

Constipation is not only about how many days have passed since your last bowel movement.

NIDDK says symptoms can include:

• Fewer than three bowel movements a week
• Hard stools that are dry or lumpy
• Pain or difficulty passing stool
• Feeling that stool remains after you finish

You can therefore be constipated even if you pass some stool every day.

The feeling of incomplete evacuation matters too.

If constipation is your main problem, see Best Constipation Treatments.

Does Constipation Always Explain the Nausea?

No.

This is where the old version of this article needed more care.

You can have constipation and nausea from one shared cause, or from two unrelated causes happening together.

Examples include:

• A medicine that causes both symptoms
• Pregnancy
• Dehydration
• IBS
• Hypothyroidism
• Diabetes
• A bowel obstruction
• Another digestive disorder

Nausea that continues after your bowel movements return to normal deserves another explanation.

9 Safe Relief Steps When Constipation Is Making You Nauseated

1. Check for Warning Signs Before Taking a Laxative

This comes first.

If you have severe abdominal pain, repeated vomiting, marked swelling, or cannot pass gas, do not assume you only need a stronger laxative.

MedlinePlus specifically advises against taking a laxative when severe stomach pain, nausea, or vomiting is present without first getting medical advice.

Sudden constipation with cramping and inability to pass stool or gas can signal an intestinal blockage.

2. Drink Enough Fluid for Your Needs

Fluid helps stool stay softer, especially when you eat more fiber.

There is no single perfect water target for everyone.

Your needs vary with:

• Body size
• Weather
• Activity
• Pregnancy
• Diet
• Kidney or heart conditions
• Medicines

NIDDK advises drinking enough water and other liquids, particularly when increasing fiber.

If a doctor has told you to limit fluids, follow that medical advice rather than forcing extra water.

3. Increase Fiber Gradually, Not Overnight

Fiber can improve constipation, but adding a large amount suddenly can make gas, cramping, and nausea worse.

NIDDK gives a general adult fiber range of about 22 to 34 grams each day, depending on age and sex.

Good sources include:

• Oats
• Whole grains
• Lentils
• Beans
• Pears
• Apples with skin
• Berries
• Vegetables
• Nuts
• Seeds

Increase fiber in stages and drink enough fluid so it can work properly.

For food ideas, see High Fiber Foods Chart for Constipation.

4. Take a Gentle Walk

Regular physical activity can help stimulate normal bowel movement.

You do not need a hard workout.

A short comfortable walk is enough to start if you feel well enough.

For more movement options, read Constipation Exercises.

5. Use the Natural Bowel Reflex After Meals

Eating naturally stimulates colon movement. This response is called the gastrocolic reflex.

NIDDK suggests that bowel training can include sitting on the toilet about 15 to 45 minutes after breakfast.

Give yourself time.

Do not ignore the urge to go when it comes.

Repeatedly delaying bowel movements can make stool harder and more difficult to pass.

6. Put Your Feet on a Small Stool

NIDDK suggests using a footstool to improve comfort while having a bowel movement.

Raising the feet can create a more squat like position.

Lean forward gently, relax your abdomen, and avoid long periods of forceful straining.

If you repeatedly feel blocked despite a strong urge to go, ask about pelvic floor dysfunction. Some people have trouble coordinating the muscles needed to empty the rectum.

7. Choose Over the Counter Laxatives Carefully

Laxatives are not one single type of medicine.

They work in different ways.

The 2023 joint AGA and ACG guideline strongly recommends polyethylene glycol for chronic idiopathic constipation and also supports several other medicines based on the clinical situation.

This corrects an error in the older article: linaclotide is not a stimulant laxative.

A pharmacist or doctor can help choose the right type, especially during pregnancy, with kidney disease, or when you take several medicines.

8. Check Your Medicines and Supplements

A new medicine can explain a lot.

NIDDK lists several products that can worsen constipation, including:

• Opioid pain medicines
• Some antidepressants
• Anticholinergic medicines
• Calcium channel blockers
• Some anticonvulsants
• Iron supplements
• Some antacids containing calcium or aluminum
• Some diuretics

A medicine may also cause nausea directly.

If both symptoms started after a medication or supplement change, tell your doctor or pharmacist.

Do not stop prescribed treatment on your own.

9. Get Medical Advice if the Pattern Keeps Returning

Occasional constipation often improves with simple care.

Repeated or chronic constipation deserves a proper explanation.

Get medical advice if:

• Self care is not working
• You are regularly constipated
• Nausea keeps returning
• You need laxatives repeatedly
• You feel blocked when trying to pass stool
• Your bowel habits have changed suddenly
• You have persistent abdominal pain
• You are losing weight without trying
• You see blood

What Is Fecal Impaction?

Fecal impaction is not simply “a bad day of constipation.”

It means a large mass of hard stool becomes stuck and cannot be passed normally.

Cleveland Clinic lists possible symptoms including:

• Constipation
• Abdominal discomfort
• Bloating
• Loss of appetite
• Nausea
• Dehydration
• Confusion in severe cases

One clue can be surprisingly misleading: watery stool.

Liquid stool can sometimes leak around an impaction, making it look as if the person has diarrhea rather than severe constipation.

NHS guidance warns about the same pattern.

Can You Remove an Impaction Yourself?

Do not attempt manual disimpaction yourself.

Severe impaction may require stronger laxatives, suppositories, enemas, or removal by a trained healthcare professional after the problem has been assessed.

Cleveland Clinic warns that improper digital disimpaction can injure the rectum and can even trigger fainting or abnormal heart rhythms.

When Could It Be a Bowel Obstruction?

This is the safety distinction that matters most.

A bowel obstruction prevents stool, gas, or intestinal contents from moving normally through the bowel.

Warning signs include:

• Cramping or severe abdominal pain
• Increasing abdominal swelling
• Nausea
• Vomiting
• Inability to pass stool
• Inability to pass gas

If constipation, nausea, and vomiting occur with inability to pass gas, seek urgent medical care.

Do not simply take progressively larger doses of laxatives.

Constipation vs Fecal Impaction vs Bowel Obstruction

What Else Can Cause Constipation and Nausea Together?

Irritable Bowel Syndrome

Irritable bowel syndrome can include constipation, abdominal pain, bloating, and other digestive symptoms.

IBS is more likely when symptoms keep returning over time and bowel changes occur together with abdominal pain.

For food guidance, read IBS Constipation Diet.

Pregnancy

Pregnancy can cause both nausea and constipation.

Hormonal changes can slow bowel movement, while nausea is common during early pregnancy.

Iron supplements used during pregnancy can add to constipation in some people.

If pregnancy is possible and your period is late, do not assume constipation is the only explanation for nausea.

Hypothyroidism

Low thyroid activity can slow body processes, including bowel movement.

Other clues can include:

• Fatigue
• Feeling cold
• Dry skin
• Weight gain
• Slower thinking

Diabetes

Diabetes can affect nerves that control digestion in some people.

Persistent constipation plus nausea, unusual thirst, frequent urination, or unexplained weight change deserves medical assessment.

Pelvic Floor Problems

Some people generate enough bowel movement but cannot relax and coordinate the pelvic muscles needed to pass stool.

This can produce:

• Long toilet sessions
• Straining
• Incomplete emptying
• Feeling physically blocked

NIDDK notes that biofeedback therapy can help when the muscles that control bowel movements are not working together correctly.

Opioid Medicines

Opioid pain medicines are a particularly strong constipation trigger.

If you take codeine, oxycodone, morphine, or another opioid and constipation develops, ask the prescriber about prevention and treatment rather than waiting for severe symptoms.

What Should You Eat When Constipation Is Making You Nauseated?

Large heavy meals can feel uncomfortable when you are already full or queasy.

Smaller meals may be easier to tolerate.

When ordinary constipation is the likely problem and obstruction has been excluded, useful fiber foods include:

• Oatmeal
• Pears
• Berries
• Prunes
• Oranges
• Beans
• Lentils
• Peas
• Broccoli
• Whole grains
• Nuts and seeds

Add them gradually.

More fiber is not automatically better when you already have a very swollen abdomen or severe nausea.

For a broader food guide, visit the Gut Health Foods Guide.

Do Prunes Help Constipation?

Prunes can help some people.

They provide fiber and naturally contain sorbitol, a carbohydrate that can draw water into the bowel.

Start with a modest amount because too much can produce gas, cramps, or diarrhea.

Does Ginger Help the Nausea?

Ginger has evidence for some types of nausea, including pregnancy related nausea, but it does not correct the underlying constipation or an obstruction.

If nausea is strong enough that you cannot eat or drink, focus on the cause rather than repeatedly adding anti nausea remedies.

Do Probiotics Fix Constipation and Nausea?

No probiotic can be assumed to treat every cause of constipation.

Different products contain different organisms and doses, and results vary.

If constipation is persistent, identify why it is happening before spending heavily on supplements.

Should You Use a Stool Softener?

Stool softeners such as docusate have been used for constipation, but they are not the same as osmotic laxatives such as polyethylene glycol.

For chronic idiopathic constipation, the joint AGA and ACG guideline gives stronger evidence based support to treatments such as polyethylene glycol than to docusate.

Ask a pharmacist or clinician which option fits your symptoms and medical history.

Can Laxatives Cause Nausea?

Yes.

Constipation may cause nausea, but some treatments can also cause it.

Mayo Clinic lists nausea, bloating, gas, cramping, or diarrhea among possible side effects of some laxatives.

If nausea becomes worse after starting a product, check the instructions and speak with a pharmacist or clinician.

What About Magnesium for Constipation?

Magnesium containing laxatives can draw water into the bowel.

They are not appropriate for everyone, especially people with significant kidney disease, because magnesium can accumulate.

Do not assume a supplement is harmless because it is sold without a prescription.

How Do Doctors Investigate Chronic Constipation?

The evaluation starts with your history.

Your doctor may ask:

• How often you pass stool
• What the stool looks like
• How long symptoms have lasted
• Whether you strain
• Whether you feel completely empty
• Which medicines and supplements you take
• Whether you have bleeding
• Whether your weight has changed

A physical examination can include checking the abdomen and, when needed, a rectal examination.

Depending on the pattern, NIDDK says tests can include blood work for anemia, thyroid disease, or celiac disease, stool testing, colonoscopy, and specialized tests of bowel or pelvic floor function.

When Should You See a Doctor for Chronic Constipation?

Arrange medical assessment if:

• Constipation is regular or long lasting
• Home treatment no longer works
• Nausea keeps returning
• You depend on laxatives
• You have a new change in bowel habits
• You have persistent abdominal pain
• You have rectal bleeding
• You have blood in the stool
• You are losing weight without trying
• You are tired all the time

NHS guidance also recommends medical review for regular constipation, regular bloating, unexplained weight loss, blood in the stool, or a sudden bowel habit change.

What Should You Avoid?

• Do not assume all nausea is caused by constipation.
• Do not keep increasing fiber when you have vomiting or cannot pass gas.
• Do not manually remove impacted stool yourself.
• Do not repeatedly use enemas without medical guidance.
• Do not stop prescribed medicines because they might cause constipation.
• Do not take several laxatives together without checking that the combination is appropriate.
• Do not ignore blood, weight loss, severe pain, or a sudden bowel habit change.

Conclusion

Can constipation cause nausea? Yes. Slow stool movement, bloating, abdominal pressure, and severe constipation can all occur with nausea, and fecal impaction can make the symptoms much stronger.

For mild uncomplicated constipation, start with normal hydration, gradual fiber, gentle activity, a regular toilet routine, and an appropriate constipation treatment when needed.

But vomiting, severe or constant pain, a very swollen abdomen, blood, fever, or inability to pass gas changes the picture.

Your next step is simple: treat mild constipation early, track whether the nausea improves when bowel movements normalize, and get medical advice when it does not.

References and Sources

1. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms and Causes of Constipation.
   https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/symptoms-causes
2. National Institute of Diabetes and Digestive and Kidney Diseases. Treatment for Constipation.
   https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/treatment
3. National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of Constipation.
   https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/diagnosis
4. NHS. Constipation.
   https://www.nhs.uk/conditions/constipation/
5. MedlinePlus. Constipation Self Care.
   https://medlineplus.gov/ency/patientinstructions/000120.htm
6. MedlinePlus. Fecal Impaction.
   https://medlineplus.gov/ency/article/000230.htm
7. Cleveland Clinic. Fecal Impaction.
   https://my.clevelandclinic.org/health/diseases/23085-fecal-impaction
8. Cleveland Clinic. Constipation: Symptoms and Causes.
   https://my.clevelandclinic.org/health/articles/4059-constipation
9. American College of Gastroenterology. AGA and ACG Guideline on Chronic Idiopathic Constipation Treatments.
   https://gi.org/journals-publications/ebgi/schoenfeld2_june2023/
10. Mayo Clinic. Nonprescription Laxatives for Constipation.
    https://www.mayoclinic.org/diseases-conditions/constipation/in-depth/laxatives/art-20045906

Internal Links + Hub

• Digestive Health and Gut Hub
• Gut Health Foods Guide
• Best Constipation Treatments
• High Fiber Foods Chart for Constipation
• IBS Constipation Diet
• Constipation Exercises
• Bloating Gurgling Stomach
• Stomach Pain After Eating
• Can Anxiety Cause Nausea?
• Foods to Eat for a Healthy Pregnancy
• Healthy Eating Lifestyle

About the Author

Frequently Asked Questions

Can constipation cause nausea?

Yes. Constipation can occur with nausea, especially when stool moves slowly and causes bloating, pressure, fullness, or reduced appetite. Severe constipation and fecal impaction can cause stronger nausea.

Why does constipation make me feel sick?

Slow bowel movement and stool retention can cause abdominal distention, pressure, discomfort, and changes in digestive signaling. These effects can leave you feeling queasy or less interested in food.

Can constipation cause vomiting?

Severe constipation or fecal impaction can occur with vomiting, but vomiting with constipation is a warning sign. NIDDK recommends prompt medical assessment, especially when you also have severe pain or cannot pass gas.

How do I know whether I have constipation?

Common signs include fewer than three bowel movements a week, hard or dry stools, painful or difficult bowel movements, straining, and feeling that you have not emptied completely.

How can I relieve nausea caused by constipation?

Treating uncomplicated constipation may reduce the nausea. Useful steps include adequate fluid, gradually increasing fiber, gentle activity, a regular bowel routine, and an appropriate constipation medicine when needed.

What is the best laxative for chronic constipation?

The right medicine depends on the cause and your health. The joint AGA and ACG guideline gives strong support to polyethylene glycol for chronic idiopathic constipation. Other medicines are used when appropriate.

Can too much fiber make constipation worse?

Yes. Increasing fiber too quickly can cause gas and bloating. Fiber also needs adequate fluid. Do not increase fiber aggressively if you are vomiting, severely swollen, or unable to pass gas.

Can constipation cause loss of appetite?

Yes. Significant bloating, abdominal pressure, or fecal impaction can make you feel full and reduce appetite. Persistent appetite loss needs assessment if it continues after constipation improves.

What are signs of fecal impaction?

Signs can include long lasting constipation, abdominal discomfort, bloating, inability to pass normal stool, appetite loss, nausea, and sometimes watery stool leaking around the hard impaction.

How can I tell constipation from bowel obstruction?

Ordinary constipation usually still allows some gas or stool to pass. Severe cramping, vomiting, abdominal swelling, and inability to pass either gas or stool can indicate an obstruction and need urgent assessment.

Can pregnancy cause constipation and nausea together?

Yes. Hormonal changes in pregnancy can slow bowel movement, while nausea is common during pregnancy. Iron supplements can also contribute to constipation in some people.

When should I see a doctor for constipation and nausea?

Get medical advice if the symptoms persist, keep returning, or come with blood, unexplained weight loss, persistent pain, fever, vomiting, or a sudden change in bowel habits. Inability to pass gas with pain and vomiting needs urgent assessment.