Talk to your doctor so you don’t run the risk of being misdiagnosed.
Ulcerative colitis (UC) is a subtype of inflammatory bowel disease that can be tricky to diagnose. Many people often think their ulcerative colitis symptoms are something else. The reason this happens is because there are a handful of digestive diseases that come with similar symptoms. However, these conditions all require different treatment, which is why getting an accurate diagnosis is crucial.
So how can you tell the difference between UC and other digestive problems?
Overlapping Symptoms of Ulcerative Colitis and Crohn’s
The most common symptoms of ulcerative colitis include:
- Bloody diarrhea
- Urgency (needing to go to the bathroom frequently)
- Rectal bleeding
- Constipation (in some cases)
- Weight loss
- Skin problems
The most common disease that may mimic UC is Crohn’s disease. After all, these are both types of inflammatory bowel disease. This is when the immune system attacks the lining of the digestive tract, causing chronic inflammation. The difference between UC and Crohn’s is simply what parts of the digestive tract the immune system is attacking. As a result, they can cause similar symptoms. The main way to tell the difference is with diagnostic testing (more on that later).
Symptoms of Ulcerative Colitis vs. IBS
Another condition that mimics ulcerative colitis symptoms is irritable bowel syndrome. This condition has no clear cause, but it causes frequent abdominal pain and a change in bowel habits. Often, the pain subsides after a bowel movement, which is not always the case with UC. People with IBS are also unlikely to experience other complications like fever or weight loss.
People with IBS may have diarrhea and constipation, but it is rarely bloody. When it is bloody, it’s usually bright red blood from hemorrhoids, and it mostly just appears on toilet paper. Bloody diarrhea from UC is usually darker and affects the color of the entire stool.
UC vs. Food- and Water-borne Infections
Another issue that may mimic UC is an infection coming from contaminated food or water. This is generally known as “food poisoning.” Often, these infections don’t last long, but some may persist and start to mimic inflammatory bowel disease.
Similar to UC, food-borne and water-borne infections can cause symptoms like:
- Rectal bleeding
- Abdominal pain
Testing to Rule Out Other Conditions
Your doctor may start by using a stool test in order to rule out an infection. This allows them to see if there are any infectious microbes in your bowel movement, and if so, which ones. Depending on the results, they will then turn their attention to making the diagnosis of ulcerative colitis.
Your doctor will ask you for a thorough recounting of your symptoms and medical history. Depending on this, they’ll order blood tests. One blood test looks for inflammatory markers, which would signal there’s an active inflammation in the body possibly related to UC or Crohn's disease. This can also help rule out IBS, since this syndrome doesn't cause inflammation.
The doctor may then order a colonoscopy to thoroughly evaluate the inside of the colon. This can allow them to see where the inflammation is happening, which can help differentiate among UC, Crohn’s, and other conditions. In some cases, an MRI or CT scan of the abdomen may help to give a better picture of what’s going on in the digestive tract.
Benefits of Adequate Diagnosis
Ulcerative colitis can have a significantly negative impact on your quality of life. Getting an accurate diagnosis and starting early therapy can help reduce those debilitating symptoms and prevent serious complications. Talk to your doctor if you think you have UC or are experiencing uncomfortable digestive symptoms. Together, you can start the process of testing and treatment.
Dr. Kayal is a gastroenterologist at Icahn School of Medicine at Mount Sinai.
- Clinical manifestations and diagnosis of irritable bowel syndrome in adults. Waltham, MA: UpToDate, 2021. (Accessed on July 1, 2021)
- Clinical manifestations, diagnosis, and prognosis of Crohn disease in adults. Waltham, MA: UpToDate, 2021. (Accessed on July 1, 2021)
- Clinical manifestations, diagnosis, and prognosis of ulcerative colitis in adults. Waltham, MA: UpToDate, 2021. (Accessed on July 1, 2021)
- Patient education: Foodborne illness (food poisoning) (Beyond the Basics). Waltham, MA: UpToDate, 2021. (Accessed on July 1, 2021)