Symptoms and Complications

Reviewed by: HU Medical Review Board | Last Reviewed: January 2018. | Last updated: January 2018

Symptoms of inflammatory bowel disease (IBD) are related to the area of the digestive tract that is affected. Ulcerative colitis (UC) affects the large intestine, and Crohn’s disease (CD) can affect any part of the digestive tract, from the mouth to the anus. Typical symptoms of both CD and UC include diarrhea, abdominal pain, weight loss, and fever.1,2 Inflammation outside the digestive tract can cause symptoms that affect the skin, eyes, joints, and liver. IBD can interfere with normal growth and development in children. It is linked to menstrual irregularities in women.

As a chronic condition, IBD tends to progress with time, and many people with IBD develop complications. For example, 5 years after diagnosis, about half of people with CD have complications. By 10 years, about 70% have complications.3


Diarrhea is frequent, loose stool. Diarrhea may get worse during disease flares.4 It is more likely to be watery if you have inflammation in the small intestine, which can occur with Crohn's disease. If the inflammation is in your large intestine, diarrhea may be bloody.4,5 Diarrhea is a risk factor for urgency or incontinence. Incontinence, or the inability to control bowel movements, is a devastating symptom. It affects many people with IBD.

In a year-long survey, 63% of respondents with Crohn’s disease and 38% of respondents with ulcerative colitis reported having diarrhea at some point.6 It was the most common symptom during a flare, occurring in 84% of respondents.

Abdominal cramps and pain

Nearly half (47%) of people with Crohn’s disease report having abdominal pain. Abdominal pain is also a common symptom for people with ulcerative colitis, with approximately 32% reporting experiencing abdominal pain.6 The pain may be constant or off-and-on.7 It often occurs after meals. Some people limit how much they eat in order to minimize the pain.8 The pain may worsen during a flare. However, many patients have pain during remission, too.9

Weight loss

For multiple reasons, weight loss is a common symptom of IBD. It is likely to occur during flares, when it can be difficult to eat. Malabsorption and bleeding can also decrease nutritional status. You may be able to identify and avoid foods that worsen your symptoms. However, too many food restrictions can also limit intake and make it difficult to eat a balance diet.


Fever may be related to the inflammatory process. It can also be a side effect of commonly used medications or a symptom of a complication.1,10


Most people with active IBD—and many people in remission—report feeling fatigue. Fatigue interferes with your ability to do physical or mental work. It can affect your quality of life and relationships.1,11 Many factors contribute to fatigue. These factors include difficulty sleeping, anemia, medications, depression, and the inflammatory process itself.


Constipation can be a symptom of complications from IBD or a side effect of medications. Specifically, a stricture or anal fissure can lead to constipation. Opioid pain relievers and iron supplements can also cause constipation.

Perianal disease

Perianal disease includes abscess, fistula, fissure, skin tags, stricture, or hemorrhoids that affect the rectum or anus. Perianal disease is often the first sign of Crohn’s disease. It is most common in people with inflammation in the colon and rectum.12 Elderly individuals and children are at the highest risk.13

Oral symptoms

Crohn’s disease can cause sores, cracks, swelling, and redness in the mouth.14 Sometimes, the lining of the mouth undergoes the same changes as the lining of the digestive tract. Other times, malnutrition and medications cause oral symptoms. Not all sores are painful. However, painful sores can interfere with eating and drinking.

Inflammation of the joints, skin, eyes, and liver

More than a third of people with IBD have symptoms outside the digestive tract.15 The joints are the most commonly affected parts outside of the digestive tract. Some people develop painful red growths under the skin during flares. A small percentage of people experience eye inflammation. Eye inflammation can be mild or severe, depending on which layer of the eye is affected. Primary sclerosing cholangitis is an inflammatory condition in the liver that often overlaps with inflammatory bowel disease. This condition causes scarring in the bile ducts. Other IBD-related liver conditions are autoimmune hepatitis and gallstones.

Menstrual irregularities

Many women report that IBD caused changes in their menstrual cycle.16 Others report that they have cyclical changes in bowel symptoms. Girls diagnosed with Crohn’s disease at a young age may go through puberty later.

Delayed growth

Delayed growth and delayed puberty can occur in young people with IBD, and this is seen more often with Crohn's disease than ulcerative colitis.17 Poor growth and poor weight gain are common Crohn’s disease symptoms for young people.18 Reasons for this include not feeling hungry, difficulty absorbing food, aversion to eating because of symptoms and pain, and some medications. Growth delays are seen at Crohn’s disease diagnosis for about 10% of children.18 Growth continues to be a problem for 7% to 27% of children, even once treatment begins. Fortunately, treatment with newer medications seems to help children with Crohn’s disease reach average heights as adults.18

Common complications of inflammatory bowel disease

In CD, the inflammation goes through the full thickness of the intestinal walls. By comparison, the inflammation in UC only affects the innermost layer of the intestinal wall. While some complications are common to both forms of IBD, in CD some complications happen because the inflammation is so deep. Some of the complications commonly experienced by people with IBD include:

  • Strictures, a narrowing of the digestive tract that can occur from scarring due to chronic inflammation
  • Ulcers and lesions, other signs of damage to the lining of the intestine
  • Abscesses, large inflamed masses
  • Fistulas, abnormal connections that form between the intestines and other organs in some people with CD
  • Anal fissures, a split or tear at the end of the anal canal
  • Toxic megacolon, a rare but serious complication of IBD in which the colon begins to widen (dilate) and causes symptoms such as bloody diarrhea, abdominal pain, fever, and rapid heart beat

IBD can increase your risk of certain digestive tract diseases, including:

IBD can also cause other related health problems, such as malnutritionanemia, and osteoporosis.

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