Diarrhea and UTI – Causes, Symptoms, Treatment

The lower digestive tract and the lower urinary tract lie very close to each other and sometimes the same cause can affect both structures. This may cause symptoms like diarrhea (sign of a gastrointestinal infection) or frequent and burning urination (signs of a bladder infection) at the same time. However, it is also possible for a problem in one tract may lead to a problem in the other tract and cause simultaneous symptoms.

Signs and Symptoms

Diarrhea is a symptom usually due to a disturbances in the digestive tract. Sometimes it can be associated with other non-digestive conditions and may also occur for no clearly identifiable reason. Usually diarrhea is acute – it arises suddenly, tends to be severe and lasts for a short period of time. Diarrhea is often accompanied by other signs and symptoms such as abdominal cramps or pain, excessive flatulence and bloating.

Urinary tract infection (UTI) symptoms include frequent urination, burning or painful urination, constant urging to urinate, lower abdominal and pelvic pain, discolored urine and strong-smelling urine. Most UTIs are ascending infections – it starts in the urethra and spreads to the bladder. The infection is often limited to this lower part of the urinary tract but can extend upwards to the liver where there may be other symptoms like flank pain.

UTI urinary tract infection

Nausea, vomiting and loss of appetite may be some of the other signs and symptoms that may occur with both diarrheal illnesses and urinary tract infections (UTIs). A fever may be present in a UTI and with infectious diarrhea. In both conditions there is the risk of dehydration or even septicemia in severe cases. Additional symptoms may be noticed in these instances. Severe dehydration and septicemia should be treated as a medical emergency.

Causes of Diarrhea and UTI

It is important to note that diarrhea is a symptom that is usually separate from a UTI. Diarrhea may occur for various reasons, both infectious and non-infectious. UTIs (urinary tract infections) are infections that affect the urinary tract, namely the urethra and bladder but sometimes extending all the way up the ureter to the kidney.

Read more on signs of UTIs.

Diarrhea Causes UTI

A range of diarrheal illnesses, whether due to an infection or not, can lead to a urinary tract infection. The watery stool laden with bacteria may reach the urethra and some of these bacteria can enter the urethra to cause a UTI. It is not only pathogenic (disease-causing) bacteria that causes diarrheal illnesses which may lead to a UTI. Even the normal intestinal flora (natural bowel bacteria) like E.coli may cause a UTI if it enters the urethra.

This is more likely to occur in females since the female urethra is shorter than the male urethra. This increases the risk of urinary tract infections, which are often due to E.coli found in the feces. This is the reason why females are more likely to suffer with UTIs. However, in the backdrop of diarrhea, even non-infectious diarrhea, this risk increases substantially due to the profuse and watery stool.

UTI Causes Diarrhea

Sometimes a UTI causes diarrhea even though there is no infection of the colon or rectum, despite the infection in the urinary tract. The exact cause why this occurs is not clearly understood. It it is believed that inflammatory chemicals in the infected portion of the urinary tract can also act on the colon. The colon and lower urinary tract, especially the bladder, lie very close to each other.

These chemicals can then cause irritation and even inflammation. This may increase movement through the colon which results in diarrhea. In less common cases a severe infection of the bladder can extend to other pelvic organs like the lower parts of the colon and rectum. Diarrhea would also occur in these cases. In rare instances certain highly pathogenic (disease-causing) microbes in the female reproductive tract may be transferred into the rectum.

Sexual Activity and STIs

Certain sexual practices may also cause both diarrhea and a UTI. For example, anal intercourse followed by vaginal intercourse can injure the rectum (proctitis) and then infect vagina. A UTI may then ensue due to the location of the urethral opening which is close to the vagina. Diarrhea may also occur as a result of the proctitis. Sometimes a sexually transmitted disease (STD) may cause an infection of both the rectum and vagina with a subsequent urinary tract infection. Infectious agents may also be transmitted through objects used during sexual activity.

Weakened Immune System

A weakened immune system may increase the risk of infections of the digestive and urinary tracts. Therefore there may simultaneous gastrointestinal and urinary tract infections. Therefore symptoms, like diarrhea and UTI symptoms, may be present at the same time. The elderly, chronically ill and people with conditions like HIV/AIDS and uncontrolled diabetes may be at greater risk of these infections due to impaired immune defenses.


Treatment of Diarrhea and UTI



Read more on how to stop diarrhea.

The loss of fluid and electrolytes with diarrhea and excessive urination in UTIs may lead to dehydration. Proper oral hydration is therefore necessary. This includes the use of oral rehydrating solutions (ORS). However, when oral hydration is not an option then intravenous (IV) fluid administration is then required. Always consult with a doctor when diarrhea and a UTI occur for proper treatement and management. This can help prevent complications.

Last updated on September 11, 2018.
