IBD, or inflammatory bowel disease, refers to a group of gastrointestinal diseases marked by chronic inflammation that affects the intestinal lining, and Crohn’s disease, ulcerative colitis (UC), and microscopic colitis are the most common types. Crohn’s disease can affect any part of the digestive tract, whereas UC and microscopic colitis specifically target the large intestine, and UC also causes ulcer formation.

The main signs and symptoms of inflammatory bowel disease include diarrhea, abdominal pain, and unexplained weight loss; ulcerative colitis potentially causes blood or mucus in the stool, and Crohn's disease leads to additional symptoms like joint pain and nausea. Symptoms can vary in severity, with periods of flare-ups and remission.

Inflammatory bowel disease is diagnosed through a combination of physical exams, blood and stool tests, endoscopy procedures to view the intestinal lining and collect biopsies, and imaging techniques like CT scans to assess the gastrointestinal tract.

Inflammatory bowel disease is managed with long-term care from a gastroenterologist, anti-inflammatory medications, and treatments for symptoms like diarrhea and pain. In some cases, surgery may be required to remove severely damaged sections of the intestine, and exclusive enteral nutrition can help induce remission, especially in pediatric cases.

Probiotics, prebiotics, and synbiotics are modestly effective in inducing remission and reducing symptoms of inflammatory bowel disease (IBD), particularly in ulcerative colitis. Cannabis, cannabinoids, resveratrol, curcumin, and vitamin D may improve symptoms, but polyunsaturated fatty acid supplements are ineffective for IBD remission or inflammation.

A Western dietary pattern may increase the risk of developing inflammatory bowel disease (IBD), and higher consumption of fruits, vegetables, and fiber is associated with a reduced risk. However, exclusion diets and a low-FODMAP diet have little to no effect on disease activity.

Mindfulness has shown potential in reducing stress in people with inflammatory bowel disease (IBD), and cognitive behavioral therapy may improve quality of life and fatigue. Fecal microbiota transplants are effective for ulcerative colitis remission, but the benefits of hyperbaric oxygen therapy and acupuncture are unclear due to study design flaws.

The exact causes of inflammatory bowel disease (IBD) are unknown, but it is thought to result from interactions among the immune system, genetics, gut microbiome, and lifestyle factors. Risk factors include smoking, certain medications, female hormones, infections, and other autoimmune diseases.