Feces and urine are two waste products formed by different systems in the body. It is also carried out of the body by different tracts (passages) and orifices (openings). Feces are the byproducts of digested food. It is formed in the large intestine (a part of the digestive tract), and expelled through rectum and anus.
Urine is a filtrate of the blood. It is formed in the kidneys, and is expelled through the urinary tract that ends in urethra. The paths taken by feces and urine in the body are physically distinct. In some very rare cases, however, one may find the presence of fecal particles in urine. This uncommon condition is medically known as fecaluria.
Why does fecaluria occur?
In fecaluria, fecal particles are expelled through urethra during the act of voiding urine. This is caused by an uncommon and abnormal connection between urinary and digestive tracts. By far, the most common abnormal connection that leads to the presence of feces in urine is enterovesical fistula.
An enterovesical fistula is an abnormal tunnel between urinary bladder and colon or rectum. Feces from colon or rectum can pass through this tunnel and enter urinary bladder. Other abnormal fistulas between these two excretory systems (such as those between colon and ureter, and between rectum and urethra) are less frequent, but still occur.
Signs and Symptoms of Fecaluria
The most obvious sign of fecaluria is the presence of feces in urine. However, one must exercise caution before diagnosing a mixture of fecal particles in urine as the rare fecaluria condition. One might see the presence of feces in expelled urine for reasons other than fecaluria. The following are some scenarios that must be excluded before concluding that the observed presence of feces in urine is due to fecaluria.
- While defecating, feces may stick to the groin area. These fecal particles may remain attached to the groin region if proper cleaning is not done after the act of defecation. During subsequent acts of urination, these fecal particles may get dislodged by the urine outflow from the urethra, resulting in a mixture of urine and feces in the toilet water.
- While sitting on the toilet seat and urinating, a little defecation may also occur simultaneously. Defecation may also precede or follow urination, resulting in the co-presence of feces and urine.
- Fecal particles that remain from prior toilet use might be confused for new fecal particles in urine.
- Blood clots may also be mistaken for fecal particles. These blood clots may be voided through urine or appear due to menstruation.
- In women, an abnormal connection between vagina and colon (technically known as enterovaginal fistula) may also occur. This could result in expulsion of some fecal particles through vaginal opening rather than urethral opening.
Read more on blood in urine.
If the presence of fecal particles in urine is due to a genuine case of fecaluria, then the following additional signs and symptoms may also be found:
- Pneumaturia, or presence of gas bubbles in urine, may also accompany feces in urine. This is caused by an entry of flatus from colon into bladder (via enterovesical fistula). In addition, gas-producing microbes in colon may also find their way into urinary bladder through enterovesical fistula. Either of these conditions can cause expulsion of flatus through urine.
- Pain in urinary bladder may be a feature of fecaluria.
- Expulsion of urine may become painful. This condition is technically known as dysuria.
- Exposure of urinary bladder to microbes from colon results in recurrent urinary tract infections (commonly abbreviated as UTI).
- Blood may also occur in urine. The presence of blood in urine is technically known as hematuria.
- Expelled urine may have a very bad, smelly odor (malodorous urine).
- There may be a recurrent urge to evacuate bowels. This condition is technically referred to as tenesmus.
- Incontinence, or involuntary urination, may also accompany fecaluria.
Read more on foamy urine.
Causes of Feces in Urine
The following are some of the potential causes of fecaluria.
- Surgery: Certain surgical procedures could lead to post-operative development of fistulas between gut and urinary system. One such example is a surgical procedure known as radical prostectomy. During the post-operative period following radical prostectomy, rectourethral fistula (fistula between rectum and urethra) formation can occur.
- Crohn’s disease: Crohn’s disease is a chronic inflammatory condition of bowels. It is one of the subtypes of inflammatory bowel diseases (commonly abbreviated as IBD). Crohn’s disease is characterized by diarrhea, abdominal pain, fatigue, anemia and weight loss. This disease has no cure. In order to stem the progress of Crohn’s disease, steroids and immunosuppressant drugs are used. When medications do not work, surgery is opted for. During the course of this disease, fistula may also develop between colon and urinary bladder. Although fistulas may also form in people with ulcerative colitis (another subtype of inflammatory bowel diseases), it is not as common as in people with Crohn’s disease.
- Cancer of rectum: Fistula can also develop in patients with rectal cancer. This is mostly caused by treatments such as colon resection and radiation therapy. Fistulas may also develop due to cancerous growth itself.
- Cancer of urinary bladder: Fistula may also develop in patients with cancer of urinary bladder. Like in cases of rectal cancer, development of fistula in patients with bladder cancer is most likely due to cancer treatments rather than the cancer itself.
- Diverticulosis: Diverticulosis refers to the abnormal formation of small pouches in the digestive tract. These pouches may also get inflamed, resulting in diverticulitis. Pus cells may collect in these pouches, resulting in abscess formation. Development of fistula between bowel and bladder is one of the complications of diverticulitis.
- Trauma: Blunt or sharp trauma could also result in formation of fistulas.
- Meckel’s diverticulum: Meckel’s diverticulum is a congenital abnormality of the small intestine. It is one of the most common embryonic malformation of gastrointestinal system that is present since birth. Development of fistula is a very rare complication of this condition.
- Infections of genitourinary system: Urinary fistulas can form as a result of infections in genitourinary system. Such infections could be caused by both bacteria (for example, actinomycosis) and fungi (for example, coccidioidomycosis). However, fistula formation in these conditions is a very rare occurrence.
- Appendicitis: Appendicitis refers to an inflammation of appendix. Fistula formation is a rare complication of appendicectomy.