Bubbles in Urine (Pneumaturia) Meaning & Causes of Bubbly Urine

What is Pneumaturia?

Pneumaturia is the term for passing gas in the urine. This may appear as gas bubbles in the urine and the passage of gas from the urethra during urination. Pneumaturia should be taken seriously as it is an indication of a compromised urinary tract which could progress to other complications if left untreated.

Pneumaturia as a symptom usually does not appear on its own and other abnormalities in the urine, changes in the urinary patterns and pelvic or abdominal discomfort/pain are often present as well. Pneumaturia may present in a manner similar to a urinary tract infection (UTI) and the various causes of pneumaturia may cause a person to be more prone to recurrent UTIs.

Meaning of Bubbles in the Urine

Pneumaturia should not be confused with frothy or foamy urine, which arises due to proteinuria. It also has to be differentiated from surface bubbles in the toilet bowl water that form when urinating as this can be due to detergents in the water. With pneumaturia, the bubbles in the urine may rise to the surface of the toilet bowl water in a manner similar to a carbonated beverage. More conclusively though, a person may notice passing gas from the urethra during urination.

Pneumaturia indicates the presence of gas in the urinary tract and most often occurs in the urinary bladder. This gas may be air and flatus from the bowel or could be a byproduct of certain gas-producing bacteria in the urinary tract. It is difficult to assess urine in the toilet bowl water and a small sample should be collected in an transparent sterile jar and held up to light to be examined.

Causes of Pneumaturia

A fistula and a bacterial infection involving the urinary tract are the more likely causes of pneumaturia although it may occur after insertion of catheter.


A fistula is a canal that joins two epithelial surfaces. In pneumaturia, the fistula may occur between the bladder and gastrointestinal tract (enterovesical) or the bladder and vagina in women (vesicovaginal).

The entericovesical fistula may be due to a connection between the bladder and colon (colovesical), rectum (rectovesical), ileum of the small intestine (ileovesical) or appendix (appendicovesical). At times a fistula may also develop between the gastrointestinal tract and other parts of the urinary tract (urethra, ureter, kidney – renal pelvis).

Apart from gas from the bowel passing into the bladder, the bacteria in the bowel may also enter the bladder thereby resulting in an infection of the bladder (cystitis) or neighboring sections of the urinary tract. Feces may also pass into the urine (fecaluria) as a colovesical fistula is the most common type of enterovesical fistula.

A fistula may be due to various causes, and is either congenital or acquired. Persistent inflammation, recurrent infections, surgical complication or tumor. This may pathology may arise either in the gut or urinary tract (less frequent). Some of the causes include :

  • Crohn’s disease
  • Abscess
  • Diverticulitis
  • Piercing injury
  • Cancer
  • Pelvis/abdominal surgery
  • Radiation therapy


The presence of gas-producing bacteria in the urinary tract may cause pneumaturia. This is more likely to occur in the bladder as the urine is stagnant for long periods/ Most infections are a consequence of bacteria entering through the urethra (ascending) or it may reach the bladder from neigboring structures, the blood stream or lymphatic system. Apart from a lower urinary tract infection, pneumaturia may also be seen in emphysematous pyelonephritis.

  • BB

    I have air coming out of my urethra sometimes when I urinate. It does not happen all the time. I noticed it happens more often after sex. Could it be a vaginal-bladder fistula? It doesn’t hurt. It just feels strange..like many small bubbles popping towards the end of urination. I don’t have an infection of any kind and it has been happening for 4+ months now. Should I be concerned, because I am very healthy besides this strange air bubbling!?

    • Hi BB. We cannot say for sure if it is a fistula. You will need further diagnostic investigations to confirm this but as you can see from article above there are many possible causes for bubbles in the urine. The question now would be whether this is in air that seems to be coming out of your bladder and if so then the route by which it got there has to be investigated. However, there is also the possibility that this gas is not air but is instead being produced within the bladder. If so then it is possible that you have an infection of sorts and the microbes within the urinary tract may be producing the gas. You can still have a urinary tract infection even if you don’t have the typical symptoms like burning urination and so on. You should consult with your doctor as soon as possible.

    • COJenn

      I have had many of the causes of this.. surgery, urologist reaching in the way kidney stoneys come out with a basket, other stones, many infections…and I have had fistula when my gall bladder surgeon messed up and instead of one laparoscopic procedure I was treated to 5 extra ones, and blood transfusions and I became septic…during healing I had a part that was cut and stiched to fix grow to a part and “heal” connecting 2 things that don’t belong…and that is normally how a fistula is caused…if you have some other damage that caused the need for healing and it usually has near damage, on 2 things that don’t belong that then grow together and create a path between things that don’t belong…since your problem is after sex…I don’t believe you have had your vagina and bladder “heal” together, mostly due to location of both of these organs…I would encourage you to see (even if you need to write it down) if it happens more than just after sex…my obgyn has always said pee after sex…as things do get intrudesed to your urethra, that leads to the bladder directly, then to more tubes (long night, can’t spell real word, but I got to have a stent there…so a doc placed tube from kidney to bladder that normally has a string left sticking out so it can be easily (painfully, very much, but super fast), but the tubes go to kidney’s, so peeing after sex, can help wash out some of the vag fluids, or other “things” that don’t belong, including air introduced through the in and out of penetration…so try thY and notes and when its time for your annual…talk to talk to your doc…but if its not happening more and more often, extra things happening, or discomfort, I would say you can wait to see doc, but the more open, honest, and forth coming you are with your docs, the better they can help you and provide better care…the more you share…the better you are – also everyone should save all their films…they come on cd anymore, but the hospital deletes and sometimes they catch stuff much earlier if they have an older imiage to compare too…hope something helps you feel better…

  • Pat

    I have been having one UTI infection after another. I have had blood in my urine a couple of times. I had bubbles in my urine which went away for awhile for appears to be back. I had an ultrasound of the bladder which was normal and yesterday I had a Cystocopy which showed nothing. Last night I had quite a few bubbles and this morning there were 2 little brownish things in the toilet, perhaps very small bladder stones. This is the second time I’ve had that happen. My doctor doesn’t seem concerned about the bubbles. She is, however, sending me for a CT of the bowels and colon.