Focal active colitis (FAC) is when a specific type of white blood cell enters tiny structures in the colon wall, causing inflammation. Various conditions can lead to FAC, such as Crohn’s disease.
Infectious colitis and irritable bowel syndrome (IBS) are other possible causes.
FAC is not a condition in its own right. It is a microscopic finding that doctors can observe using diagnostic tools. Diarrhea is the symptom that most often cooccurs with FAC, but
Learn more about focal active colitis, including symptoms, causes, diagnosis, treatment, and when to call a doctor.
FAC is when glands in the colon, known as crypts, become inflamed due to the infiltration of a specific type of white blood cell.
These crypts, which some doctors also call crypts of Lieberkühn, are present between the cells of the intestinal lining. When the white blood cells, or neutrophils, get between these cells or inside the crypts, it causes inflammation. This is known as cryptitis.
Neutrophils are responsible for killing harmful microbes. They are part of the immune system and the
However, sometimes there are no symptoms. A doctor may find FAC during a colonoscopy screening. Colonoscopies are tests in which a doctor inserts a tiny camera into the colon via the rectum to look for changes in the colon wall.
The causes of FAC are varied, and
- Crohn’s disease
- infectious colitis, which is inflammation of the colon due to an infection
- ischemic colitis, which is a reduction in blood supply to the colon
- medications, including:
As the causes range in severity, FAC may or may not be cause for concern.
Doctors identify FAC via a microscopic exam. This involves undergoing a colonoscopy with a biopsy, which means they will take a small sample of tissue during the procedure. A laboratory then analyzes this tissue, which may reveal the presence of neutrophils in several adjoining crypts.
The results of the microscopic exam cannot indicate whether or not the cause of the FAC is concerning. Doctors may need to perform additional tests to find the cause.
Doctors do not treat FAC itself. Instead, they treat what is causing it.
Treatment for Crohn’s disease
- dietary changes to help reduce symptoms
- medications to help manage inflammation
- bowel rests, which include getting nutrition via liquids or an intravenous (IV) line to give the gut a chance to heal
- surgery to remove part or all of the colon
Some researchers believe that disease-causing bacteria, or healthy bacteria that become pathogenic under certain conditions, could play a role in Crohn’s disease. A 2021 meta-analysis of previous studies found that antibiotic treatment greatly improved symptoms.
Treatment for IBS
- dietary changes to help reduce symptoms
- medications to help manage constipation or diarrhea
- therapies to help reduce conditions that can affect digestion, such as:
Antibiotics can also be a treatment for IBS. This is because there is
One of the treatment approaches for SIBO and dysbiosis is antibiotics.
Not every person with infectious colitis requires treatment, as it can
Treatment of ischemic colitis involves medical management. This may include measures such as:
- IV fluid resuscitation, the administration of fluid through a vein
- supplemental oxygen
- allowing the bowel to rest by giving food that does not require digestion
If this does not work, a person may require surgery.
Below are some answers to common questions about FAC.
Is FAC dangerous?
This depends on what is causing the FAC. In some people, FAC
How is it different from ulcerative colitis (UC)?
UC is a distinct medical condition that
A person with unexplained diarrhea, abdominal cramps, or other digestive symptoms should speak with a doctor. This does not necessarily indicate FAC, but it may suggest a person has a medical condition that requires treatment. In some cases, doctors may find evidence of FAC, but there are many causes for these symptoms.
A person should seek immediate medical attention if they have:
- sudden, severe pain in the abdomen
- bloody diarrhea
This could indicate ischemic colitis, which can require treatment.
Focal active colitis (FAC) is a microscopic finding in the colon. It occurs when white blood cells, known as neutrophils, enter crypts in the wall of the colon. It indicates the presence of inflammation in a small area.
FAC does not always occur with symptoms, but if it does, they may include diarrhea and weight loss. Various conditions can cause FAC, including Crohn’s disease, infectious colitis, IBS, ischemic colitis, and certain medications.
Doctors treat FAC by addressing the condition that is causing it.