Quick Answer: Can an Enlarged Prostate Cause Constipation?
Usually, an enlarged prostate (BPH) does not directly cause constipation. BPH primarily affects the urinary tract because the prostate surrounds part of the urethra.
- Constipation and BPH can occur at the same time, particularly in older adults.
- Constipation may worsen urinary symptoms such as urgency, frequency or difficulty emptying the bladder.
- Persistent constipation should not automatically be blamed on the prostate because diet, medicines, dehydration, inactivity, diabetes, thyroid disease and bowel disorders are among many other possible causes.
- If you have both constipation and difficulty urinating, treating the constipation may sometimes help urinary symptoms, but persistent urinary problems still need appropriate evaluation.
Men with an enlarged prostate sometimes notice constipation at the same time and understandably wonder whether one condition is causing the other.
The relationship is more complicated than simply saying that a large prostate presses against the bowel.
Benign prostatic hyperplasia (BPH) primarily affects the urinary system, while constipation is a bowel disorder. However, the bowel, bladder and pelvic-floor muscles are located close together and can influence each other’s function.
Does BPH Directly Cause Constipation?
In most men, no.
The prostate is located:
- below the bladder;
- in front of the rectum;
- and around the first part of the urethra.
When BPH develops, the main mechanical problem is narrowing or increased resistance around the urethra. This can contribute to:
- a weak urine stream;
- difficulty starting urination;
- incomplete bladder emptying;
- urinary urgency;
- frequency;
- and nocturia.
BPH Should Not Be Described as a Tumor Blocking the Colon
Benign prostatic hyperplasia is noncancerous growth of prostate tissue. It should not normally be described as an “external tumor” that grows into the colon and blocks stool. Persistent constipation deserves its own assessment rather than automatically being attributed to BPH.
How Are Constipation and Urinary Symptoms Connected?
Although BPH usually does not directly cause constipation, bowel and urinary symptoms can influence one another.
Several mechanisms may contribute:
-
A full rectum can affect bladder function.
Stool accumulation and rectal distension may influence bladder activity because the bowel and bladder occupy the same pelvic region. -
The bowel and urinary tract share pelvic-floor muscles.
Problems relaxing or coordinating these muscles may contribute to both difficult bowel movements and difficulty urinating. -
Straining may increase pelvic pressure.
Repeated straining during bowel movements may make pelvic or urinary discomfort more noticeable. -
Constipation and urinary symptoms share some risk factors.
Increasing age, reduced physical activity, certain medicines and some medical conditions can contribute to both problems.
What Is Constipation?
Constipation does not simply mean failing to have a bowel movement every day.
You may have constipation if you regularly experience one or more of:
- fewer than three bowel movements per week;
- hard, dry or lumpy stools;
- difficulty or pain when passing stool;
- frequent straining;
- or a feeling that you have not completely emptied your bowel.
Normal bowel frequency varies between individuals, so changes from your usual pattern also matter.
What Else Can Cause Constipation in a Man With BPH?
If you have both an enlarged prostate and constipation, do not assume that the prostate is responsible.
Common causes and contributing factors can include:
- Not eating enough fiber
- Not drinking enough fluid or becoming dehydrated
- Low physical activity
- Ignoring the urge to have a bowel movement
- Changes in routine or diet
- Certain medicines or supplements
- Diabetes
- Hypothyroidism
- Pelvic-floor or defecatory disorders
- Irritable bowel syndrome or other gastrointestinal conditions
- Intestinal obstruction or another structural bowel condition in less common but important situations
Can Medicines Cause Both Constipation and Urinary Problems?
Yes. Reviewing your medicines is particularly useful if constipation appeared after starting a new treatment.
Medicines that may contribute to constipation include some:
- anticholinergic medicines;
- calcium-channel blockers;
- iron supplements;
- opioid pain medicines;
- antidepressants;
- and other medicines depending on the individual.
Some medicines can also worsen difficulty urinating in men with BPH.
Do Not Stop Prescription Medicines on Your Own
If you think a medicine is worsening constipation or urination, discuss it with your doctor or pharmacist before changing the dose or stopping treatment.
What Can You Do About Constipation?
For uncomplicated constipation, several practical measures may help.
-
Increase dietary fiber gradually.
Useful sources include vegetables, fruit, legumes, oats and whole-grain foods. -
Drink adequate fluids during the day.
Fiber works better when fluid intake is sufficient. -
Remain physically active.
Regular activity can support normal bowel function. -
Respond to the urge to have a bowel movement.
Repeatedly delaying bowel movements can contribute to constipation. -
Try a regular bowel routine.
Allow enough time to use the toilet without rushing or excessive straining. -
Discuss laxatives when needed.
A healthcare professional may recommend a fiber supplement or an osmotic laxative such as polyethylene glycol for appropriate patients.
What If You Also Have Nocturia?
Men with BPH are sometimes told to reduce fluids before bedtime because this may reduce nighttime urination.
That does not mean deliberately becoming dehydrated.
A practical approach may be to:
- drink adequately earlier in the day;
- avoid very large amounts of fluid close to bedtime;
- reduce evening caffeine and alcohol if they worsen urinary symptoms;
- and follow any individual fluid instructions given for heart or kidney disease.
Can Treating Constipation Improve Urinary Symptoms?
It may help in some people.
Because bowel distension and pelvic-floor dysfunction can influence bladder function, relieving constipation may reduce some urinary symptoms when both conditions occur together.
However, improvement in constipation does not prove that BPH has been treated.
Persistent symptoms such as:
- weak urine flow;
- difficulty starting;
- significant incomplete emptying;
- urinary retention;
- or repeated nocturia
should still be assessed separately.
Read our complete guide to enlarged prostate symptoms .
When Should Constipation Be Checked by a Doctor?
Arrange medical evaluation if:
- constipation persists despite reasonable self-care;
- your bowel pattern has changed significantly;
- you regularly need laxatives;
- you have significant abdominal discomfort;
- or constipation occurs together with worsening urinary symptoms.
Seek Prompt Medical Attention If You Have:
- inability to urinate at all;
- blood in your stool or rectal bleeding;
- constant or severe abdominal pain;
- inability to pass stool or gas;
- vomiting or fever;
- unexplained weight loss;
- or painful, frequent urination together with fever or chills.
Dr. Albana’s Note
When a man has both constipation and an enlarged prostate, I would avoid automatically assuming that the prostate is physically blocking the bowel.
I would first look at both problems separately: his bowel habits, diet, fluid intake, medications and other causes of constipation, together with the severity of his urinary symptoms and whether he is emptying his bladder properly.
Treating constipation is worthwhile and may sometimes make urinary symptoms easier to manage, but persistent difficulty urinating still deserves its own evaluation.
— Dr. Albana Greca, MD, MMedSc, Family Physician / General Practitioner
Most Asked Questions About BPH and Constipation
Can a large prostate press on the bowel?
BPH primarily affects the urethra and urinary tract. Direct bowel compression is not the usual explanation for constipation in men with BPH, so persistent constipation should be evaluated for common bowel, dietary, medication and medical causes.
Can constipation make it harder to urinate?
It can. A full rectum, pelvic-floor dysfunction and straining may influence bladder and urinary function. Studies have found an association between constipation and lower urinary tract symptoms in men.
Can treating constipation improve BPH symptoms?
Treating constipation may improve some urinary symptoms when bowel and bladder dysfunction occur together, but it does not directly treat prostate enlargement itself.
Should I drink less water because I have BPH?
Avoiding excessive fluid close to bedtime may help nocturia, but inadequate fluid intake can contribute to constipation and dehydration. Your appropriate fluid intake depends on your health, medications and any advice given by your healthcare professional.
Is constipation a normal symptom of BPH?
No. Constipation is not considered a typical lower urinary tract symptom of BPH. If both occur, each deserves appropriate consideration.
When is constipation concerning?
Seek medical assessment if constipation persists or occurs with rectal bleeding, blood in the stool, constant abdominal pain, inability to pass gas, vomiting, fever or unexplained weight loss.
Related BPH Guides
Medical References
-
National Institute of Diabetes and Digestive and Kidney Diseases.
Enlarged Prostate (Benign Prostatic Hyperplasia).
NIDDK -
National Institute of Diabetes and Digestive and Kidney Diseases.
Symptoms & Causes of Constipation.
NIDDK Constipation -
National Institute of Diabetes and Digestive and Kidney Diseases.
Treatment for Constipation.
NIDDK Constipation Treatment -
Thurmon KL, Breyer BN, Erickson BA.
Association of bowel habits with lower urinary tract symptoms in men:
findings from the 2005–2006 and 2007–2008 National Health and
Nutrition Examination Survey.
Journal of Urology. 2013.
PubMed -
Averbeck MA, Madersbacher H.
Constipation and LUTS—How Do They Affect Each Other?
International Braz J Urol. 2011.
PubMed
Medical information notice: This article provides general educational information and does not replace individualized assessment. Constipation and urinary symptoms can have several causes, and persistent or worsening symptoms should be discussed with a healthcare professional.
Written & medically reviewed by Dr. Albana Greca, MD, MMedSc • Family Physician / General Practitioner • Last medically reviewed: August 2026