Diverticulitis is a common digestive disease characterized by inflammation of diverticula, which are small pouches that can form in the wall of the colon. Diverticulitis develops when one or more diverticula become blocked or infected, causing pain and discomfort in the lower abdomen. This condition is fairly common, affecting over 200,000 Americans each year. Many people wonder whether the inflammation and infection of diverticulitis would be detectable through blood work. In this article, we’ll explore how diverticulitis can be diagnosed, examine what types of changes may occur in the blood with this condition, and discuss whether these changes would be likely to show up on routine laboratory testing. Having a better understanding of how diverticulitis could potentially impact blood work can help individuals understand the scope of diagnostic testing for this digestive disease.
How is diverticulitis typically diagnosed?
Diverticulitis is often diagnosed based on a person’s symptoms, medical history, and imaging tests. Typical symptoms that may lead to a diverticulitis diagnosis include:
- Lower abdominal pain, usually on the left side
- Bloating and abdominal tenderness
- Nausea or vomiting
- Constipation or diarrhea
- Fever
If a person has previously been diagnosed with diverticulosis, a condition where pouches form in the colon but are not infected, then acute onset of abdominal pain and fever could point to a diverticulitis flare-up. Imaging tests are also very helpful in diagnosing diverticulitis. A CT scan can show diverticula in the colon and any localized inflammation or abscess that has developed. An ultrasound may also be used to detect diverticulitis, especially in cases where CT contrast dye needs to be avoided.
While imaging and clinical presentation are the main ways diverticulitis is identified, a physician may order laboratory blood tests as part of an initial diagnostic workup. A complete blood count test can check for signs of infection or inflammation in the blood. However, diverticulitis will not necessarily show up directly on routine blood work. Next, we’ll explore what types of blood test changes may or may not occur with this condition.
What types of changes may occur in the blood with diverticulitis?
When diverticula become inflamed or infected, the colon tissue at these sites is damaged. This can lead to localized bleeding, pus, swelling, and other issues. Some of these effects may spill over into the bloodstream. However, diverticulitis is typically limited to a small portion of the large intestine. Many cases will not necessarily result in detectable abnormalities in a complete blood count or other standard blood tests. But there are a few key changes that may be seen in some instances:
Elevated white blood cell count
Diverticulitis involves infection and inflammation, which can prompt the body to produce more white blood cells to fight it off. So an elevated white blood cell count may occur. But while leukocytosis (high white cells) can indicate an infection, this non-specific finding does not pinpoint diverticulitis as the cause.
High neutrophils
One type of white blood cell, neutrophils, may increase specifically during bacterial infection and inflammation. So a high neutrophil count in the differential part of a complete blood count could indicate an active diverticulitis infection.
Anemia
Some cases of diverticulitis have associated bleeding from the inflamed pouches in the colon. If bleeding is significant, it can lead to anemia or lower than normal hemoglobin/red blood cell levels.
Elevated CRP
C-reactive protein (CRP) is a marker of systemic inflammation produced by the liver. If diverticulitis spreads significant inflammation through the bloodstream, CRP levels may be elevated on blood testing.
However, these types of blood test changes are not guaranteed with diverticulitis. Mild cases may not affect white blood cell count or CRP at all. And not all patients experience appreciable bleeding to impact hemoglobin/hematocrit. Next, we’ll go over whether diverticulitis would show up on routine blood work.
Would diverticulitis show up on routine blood tests?
In most cases, diverticulitis is unlikely to directly show up as an abnormal finding on routine blood work like a comprehensive metabolic panel or complete blood count. Some reasons why include:
- Diverticulitis is typically localized – Most inflammation and infection is contained to a segment of the large intestine, without systemic effects.
- No specific blood marker exists – While inflammation/infection can affect cell counts, there is no unique biomarker to identify diverticulitis as the cause.
- Effects may be subtle – Such as mild leukocytosis or minimal changes in CRP, which are non-specific findings.
- Blood test results can be normal – Particularly in uncomplicated cases without significant bleeding or immune response.
So in the majority of diverticulitis cases, the standard complete blood count (CBC), basic metabolic panel (BMP), and other routine blood work is expected to be within the normal range. However, for some individuals, blood test results can be impacted to show leukocytosis, high neutrophils, elevated CRP, or anemia. These changes offer clues that infection or inflammation is present and can support a diverticulitis diagnosis – but are not definitive on their own.
Are special blood tests used for diagnosing diverticulitis?
While routine blood tests may not directly indicate diverticulitis, specialized markers in the blood can sometimes be useful when this condition is suspected:
Fecal calprotectin
This non-specific inflammatory protein is released by white blood cells. Levels increase significantly in the stool during intestinal inflammation. Elevated fecal calprotectin can help distinguish inflammatory bowel conditions like diverticulitis from non-inflammatory issues like irritable bowel syndrome.
C-reactive protein and lactoferrin
As mentioned, CRP is a non-specific marker of inflammation that could rise in diverticulitis. Testing for lactoferrin, which is released from white blood cells during infection, can provide additional evidence of an inflammatory condition if elevated.
Complete blood count with differential
Beyond just overall counts, looking at the types of white blood cells present could reveal neutrophilia – a clue that diverticulitis or acute bacterial infection may be present.
These types of specialized tests may be ordered if diverticulitis is being strongly considered as a diagnosis. However, imaging through CT scan or ultrasound remains the primary method of confirming diverticulitis.
Can you have diverticulitis without changes in blood work?
It is very possible to have diverticulitis without any abnormalities showing up in blood work. As diverticulitis is typically localized in the colon, mild or even moderate cases often don’t create systemic changes detectable in routine blood testing. Even when the condition is severe enough to cause pain and complications like abscesses or perforation, the resulting inflammation and infection may not spill over significantly into the bloodstream.
Normal complete blood count results with diverticulitis can occur when:
- Inflammation is confined to a small portion of the bowel
- No significant bleeding into the gastrointestinal tract occurs
- The body’s immune response remains modest
- A course of antibiotics is already limiting the infection
Up to a quarter of patients hospitalized with acute diverticulitis have been found to have normal white blood cell counts. So a lack of indicators in the blood does not rule out a diagnosis of diverticulitis when characteristic symptoms and CT findings are present. However, if blood work changes like leukocytosis are found, they can support diagnosing this condition.
Can diverticulitis ever be diagnosed through blood testing alone?
Relying solely on blood testing to diagnose diverticulitis is difficult. While there are sometimes clues in the blood, such as high neutrophils, elevated CRP, or anemia, these are non-specific and could be explained by numerous conditions besides diverticulitis. Without clear cross-sectional imaging showing the characteristic sites of inflammation in the colon itself, diverticulitis cannot be definitively diagnosed from blood abnormalities alone. However, blood tests may be used to support a suspected diagnosis of diverticulitis that needs further confirmation through methods like CT scan.
Conclusion
In summary, mild to moderate cases of diverticulitis often will not show any discernable changes on routine blood tests like a CBC or basic metabolic panel. This condition is usually localized to portions of the colon initially. However, diverticulitis can sometimes cause increased white blood cells, neutrophils, CRP, and other markers indicating infection or inflammation. And significant bleeding may result in anemia. While these blood test results can be consistent with diverticulitis, they are not specific enough alone to make a diagnosis without confirmatory imaging through CT scan, ultrasound, or other methods that directly assess the colon itself. Mild forms of diverticulitis can certainly occur without any abnormalities in blood work. However, when available, looking at specialized markers in the blood for inflammation and infection can provide supportive information when diverticulitis is included in the differential diagnosis. Overall, blood testing plays an adjunctive role but is not the primary method for diagnosing diverticulitis itself.