Inflammatory bowel diseases (IBD) including Crohn’s disease and ulcerative colitis (UC) can have similar symptoms, which may also mimic other medical conditions.
To understand how other health problems can look like IBD, it helps to understand the differences between the two main types of IBD.
For example, while Crohn’s and UC can both cause diarrhea, bleeding, and abdominal pain, UC inflammation is limited to the colon’s (large intestine) lining, says Stephen J. Bickston, MD, the associate chief of gastroenterology at Virginia Commonwealth University (VCU) Health Medical Center in Richmond. “Bloody diarrhea is its most common presentation, and persistent bleeding from UC can cause anemia.”
Unlike UC, Crohn’s inflammation can affect any part of the digestive tract, from mouth to anus. It may reach deeper layers of the intestine, and can cause more varied symptoms than UC, says Dr. Bickston.
Because of symptom overlap between IBD and other gastrointestinal (GI) conditions, it can be difficult to tell which you have. But with the right diagnostic tests, your healthcare provider can pinpoint the source.
1. Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS), a chronic disorder of gut-brain interaction, is caused by changes in the muscles and nerves that control sensation and movement in the digestive system.
“IBS is a diagnosis based on symptom patterns rather than discrete findings on imaging or pathology, but most of the symptoms that can be experienced with inflammatory bowel disease can also happen in IBS,” says Abby Lochmann-Bailkey, MD, a gastroenterologist with SSM Health in Madison, Wisconsin. But people with IBD can also have IBS, she says, which can make diagnosis tricky.
Abdominal pain
Constipation
Diarrhea
Bloating
Gas pain
Changes in bowel movement appearance
IBS almost never causes weight loss or bleeding, Bickston says. “It is also very unusual for the pain of IBS to awaken a person from sleep.”
Both IBS and IBD are lifelong conditions of the GI tract. But, unlike IBD, IBS does not involve the immune system or cause inflammation and symptoms in other parts of the body.
2. Celiac Disease
Celiac disease, like IBD, is a chronic autoimmune disorder of the digestive system, in which the immune system attacks the body instead of defending it when it’s exposed to the protein gluten. The inflammation that results can cause damage to the small intestine. Eating foods that contain gluten — like bread, pasta, and other foods made from wheat, barley, and rye — triggers the immune response, causing inflammation.
When you have celiac disease, you can experience a wide variety of symptoms that also occur in IBD, says Dr. Lochmann-Bailkey.
Symptoms of celiac disease include:
Bloating
Frequent diarrhea
Constipation
Excess gas
Lactose intolerance
Loose, greasy, foul-smelling bowel movements
Abdominal pain
Nausea and vomiting
“Celiac disease can be mistaken for IBD, especially as it often presents early in life and can cause anemia, weight loss, diarrhea, and vitamin deficiencies,” says Bickston. “This is a nuanced circumstance, as celiac disease is more common in people with IBD than the general public, so patients may have both.”
Celiac disease and IBD can both affect your body’s ability to absorb essential nutrients. But their causes differ: eating gluten triggers celiac’s immune response, whereas IBD triggers are more complex. Celiac causes damage to the lining of the small intestine, but IBD may damage other areas of the GI tract, too, as previously described.
3. Hemorrhoids
Hemorrhoids are swollen, inflamed veins around your anus or rectum. You can have internal hemorrhoids, which affect the lining of the lower part of your rectum and internal anus, or external hemorrhoids, which occur under the skin around your anus.
Common hemorrhoid symptoms include:
Anal itching
Tender lumps near your anus
Pain in and around your anus that worsens with sitting
Rectal bleeding
Symptoms like rectal bleeding can look similar to IBD, but your healthcare provider can help you figure out which you have.
“Hemorrhoids often present with intermittent rectal bleeding that might raise suspicion of ulcerative colitis, but it is rare for bleeding hemorrhoids to cause anemia,” says Bickston. “They are most likely to produce streaks or drops of red blood with normal-colored stool, rather than bloody diarrhea, as with [IBD].”
4. Infectious Diarrhea
Bacterial and fungal infections can cause diarrhea that may look similar to IBD symptoms. The most common diarrhea-causing pathogens include the bacteria salmonella, Mycobacterium, Shigella, Campylobacter jejuni, Yersinia enterocolitica, Clostridioides difficile, and E. coli, as well as the fungi Coccidioides and Histoplasma.
Symptoms of infectious diarrhea can include:
Fever
Bloody stools
Stools with mucous
Severe abdominal pain
Bloody diarrhea and abdominal pain may cause your healthcare provider to suspect an IBD. “Infectious diarrhea can start abruptly and can include blood in stools, which is why it is important to test stools for infection,” says Lochmann-Bailkey.
5. Segmental Colitis Associated With Diverticulosis (SCAD)
Segmental colitis associated with diverticulosis (SCAD) is a condition that causes inflammation in the lining of the colon. Diverticulosis is the condition of having small pouches form in the GI tract; they typically bulge out through the walls of your colon and can become inflamed. Having inflamed, infected, or torn diverticula is called diverticulitis.
Unlike diverticulitis, SCAD causes inflammation in the intestinal lining around those pouches, but not in the pouches themselves.
Symptoms of SCAD may include:
Lower abdominal pain
Chronic diarrhea
Blood in your stool
SCAD can look similar to IBD in some imaging and other diagnostic tests, but isn’t mistaken for IBDs as often as other conditions, says Lochmann-Bailkey. Although they may share some symptoms, providers can quickly tell IBD apart from SCAD with other imaging tests or by using a scope to visualize the lining of the GI tract.
The Takeaway
Several gastrointestinal conditions cause symptoms like abdominal pain and bloody diarrhea, which can sometimes be mistaken for an inflammatory bowel disease (IBD), including Crohn’s disease or ulcerative colitis.
The most common conditions that mimic IBD include irritable bowel syndrome (IBS), celiac disease, hemorrhoids, infectious diarrhea, and segmental colitis associated with diverticulosis (SCAD).
If you have any new gastrointestinal symptoms or a change in bowel habits, talk to your doctor, who can help confirm a diagnosis and create a treatment plan.
