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.