Symptoms and Complications

Reviewed by: HU Medical Review Board | Last reviewed: March 2024 | Last updated: March 2024

Inflammatory bowel disease (IBD) affects the digestive tract. There are 2 main types of IBD which affect different parts of the digestive tract. Ulcerative colitis affects the large intestine. Crohn’s disease can affect any part of the digestive tract, from the mouth to the anus. Both types of IBD have similar symptoms.1,2


Diarrhea is frequent, loose stool. Diarrhea may get worse during an IBD flare-up. IBD causes watery diarrhea. There might be blood or mucus in the stool as well. Diarrhea can cause the body to lose a lot of water (dehydrate).1-4


Constipation can make it difficult to have a bowel movement. It can be due to IBD. For example, a blockage in the intestines caused by inflammation can lead to constipation. It can also be a side effect of certain medicines.3,4


IBD can make it harder to control bowel movements. People with IBD may get an urgent need to use the bathroom many times during the day.3,4


The inflammation in the intestines due to IBD can cause tenesmus. This is when people feel the need to have a bowel movement without being able to do so.3

Abdominal cramps and pain

Abdominal pain is common in people with IBD. The pain may be constant, or it may come and go. The pain may worsen during a flare-up. Stress and certain foods can make the pain worse.2,3

Weight loss

Weight loss is a common symptom of IBD. If you have IBD, you may need to identify and avoid foods that worsen your symptoms. But too many food restrictions can make it difficult to eat a balanced diet. IBD can also make it harder for your body to absorb nutrients from food.2

Nausea and vomiting

IBD, especially Crohn’s disease, can make you feel nauseous or feel like you need to throw up. This can lead to loss of appetite or not wanting to eat.1,4


Fever may be:1

  • Related to the inflammation caused by IBD
  • A side effect of commonly used medicines
  • A symptom of a complication


Many people with IBD experience fatigue. This can interfere with your ability to do physical or mental work. Many factors contribute to fatigue. These factors include:2

  • Difficulty sleeping
  • Anemia
  • The medicines you take
  • Depression
  • The inflammatory process


Anemia is when your body does not have enough red blood cells. This can be due to losing blood during bowel movements. IBD can also make it difficult to absorb the necessary nutrients from food, which can lead to anemia.1,3

Oral symptoms

IBD can cause sores, cracks, swelling, and redness in the mouth. This is more common in people with Crohn’s disease. Lack of certain nutrients might also cause mouth sores.5

Menstrual irregularities

Many women report that IBD caused changes in their menstrual cycle. Others report that they have cyclical changes in IBD-related symptoms. IBD may change the length and regularity of the menstrual cycle and make it more painful.6

Common complications of IBD

One set of complications due to IBD involves damage to the digestive tract. There are different ways in which IBD might damage the digestive tract. Some examples are:1,7

  • Strictures – a narrowing of the digestive tract that can occur from scarring due to ongoing (chronic) inflammation
  • Abscesses – infected masses in the intestine
  • Fistulas – abnormal connections that form between the intestines and other organs
  • Anal fissures – a split or tear at the end of the anal canal
  • Perianal disease – abscesses, fistulas, fissures, skin tags, strictures, or hemorrhoids that affect the rectum or anus
  • Toxic megacolon – a rare but serious complication of IBD in which the colon begins to widen and stops working

The damage caused by the inflammation due to IBD can lead to other health problems as well. These include:1,8

  • Arthritis – inflammation and pain in the joints
  • Osteoporosis – weakened bones
  • Liver failure
  • Inflammation of the eyes or skin
  • Delayed growth and delayed puberty
  • Gallstones
  • Colon cancer

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