Everything You Need to Know About Inflammatory Bowel Disease

What is Inflammatory Bowel Disease (IBD)?

Inflammatory Bowel Disease (IBD) is a group of autoimmune disorders (chronic inflammatory conditions) that affect the gastrointestinal (GI) tract. The two main types of IBD are Crohn's Disease and Ulcerative Colitis.

Over 3 million people in the United States alone are living with inflammatory bowel disease.

Two Types of IBD

Crohn's Disease: This condition can affect any part of the GI tract, from the mouth to the anus, but it most commonly impacts the end of the small intestine (ileum) and the beginning of the colon. It can involve multiple layers of the bowel wall and cause symptoms like abdominal pain, diarrhea, weight loss and fatigue. The inflammation in Crohn's disease can be patchy, with healthy tissue in between affected areas.

Ulcerative Colitis: This type of IBD primarily affects the colon and rectum. It causes inflammation and ulcers in the innermost lining of the colon. Unlike Crohn's, ulcerative colitis tends to be continuous (without healthy tissue between affected areas) and affects only the colon and rectum. Symptoms include diarrhea (often with blood or pus), abdominal cramps, and an urgent need to use the bathroom.

Who is affected by Crohn’s & Colitis?

While Crohn’s and Ulcerative Colitis are seen in people of all ages, it’s most commonly diagnosed between the ages of 15 and 35 with a second peak onset that occasionally occurs in people between the ages of 50 and 60.



While inflammatory bowel disease can affect both men and women, there’s some studies to suggest that colitis is slightly more common in men while Crohn’s is slightly more diagnosed in women.

People who have immediate family members with IBD (sibling, parent or child) are 10-20% more likely to develop an inflammatory bowel disease versus someone with no family history.

IBD is more common in certain ethnic groups, particularly people of Ashkenazi Jewish descent, who have a significantly higher risk of developing IBD. However, it also affects people of other ethnicities, and its incidence has been rising in Black, Hispanic, and Asian populations in the U.S. and globally.

Other risk factors for developing Crohn’s Disease or Ulcerative Colitis include smoking tobacco, diets high in processed foods and low fiber and use of non-steroidal anti-inflammatory medications.

Inflammatory Bowel Disease Symptoms

General Symptoms of IBD may include but are not limited to:

  • Chronic Diarrhea: Frequent, loose or watery stools, often accompanied by urgency.
  • Abdominal Pain and Cramping: Persistent or intermittent pain, typically in the lower abdomen.
  • Blood in Stool: This is more common in ulcerative colitis, where inflammation causes ulcers and bleeding in the colon.
  • Fatigue: Ongoing tiredness and lack of energy due to inflammation, malnutrition, or anemia.
  • Weight Loss: Unintentional weight loss due to poor nutrient absorption or loss of appetite.
  • Loss of Appetite: A reduced desire to eat, often linked to nausea or abdominal discomfort.
  • Fever: Low-grade fevers can accompany flare-ups due to inflammation.
  • Specific Symptoms by Condition:

Crohn's Disease:

  • Can affect any part of the gastrointestinal tract (from mouth to anus).
  • May cause mouth sores.
  • Often leads to fistulas (abnormal connections between organs) and abscesses.
  • Symptoms can be patchy, affecting different parts of the intestines.

Ulcerative Colitis:

  • Affects only the colon (large intestine).
  • Symptoms are often more continuous, starting from the rectum and spreading upward.
  • Bloody diarrhea and rectal bleeding are more common.

Systemic Symptoms (Less Common):

  • Joint Pain: Inflammation in the joints (arthritis).
  • Eye Inflammation: Conditions such as uveitis or episcleritis.
  • Skin Conditions: Rashes or ulcers, particularly erythema nodosum and pyoderma gangrenosum.
  • Mouth Sores: Aphthous ulcers, particularly with Crohn's disease.

What causes Inflammatory Bowel Disease?

IBD is thought to result from an inappropriate immune response, where the body's immune system mistakenly attacks the GI tract. While the exact cause is unknown, factors like genetics, environmental triggers and immune system abnormalities contribute to the disease.

How is IBD diagnosed?

IBD is diagnosed through a combination of your medical history (including whether any immediate family members have IBD) as well as a physical examination. Your doctor may ask about symptoms such as unexplained weight loss, diarrhea/bowel movement habits, abdominal pain and more. 

They will likely run blood tests including but not limited to: Sedimentation Rate (SED rate), C-Reactive protein, complete blood counts, vitamin levels and more. Your doctor may also run stool tests that check for bacterial and inflammation in your intestines. They may check for things like the bacteria H. pylori and the protein calprotectin which indicates inflammation. 

Other testing that may be performed include endoscopies which procedure involves inserting a flexible tube with a camera to examine the gastrointestinal tract.

An upper endoscopy may be done to look for Crohn’s disease in the upper digestive tract (including esophagus, stomach & duodenum). A colonoscopy may also be performed. A colonoscopy examines the colon and rectum for signs of Crohn’s Disease and Ulcerative Colitis. A biopsy may also be performed during a colonoscopy. 

MRIs and CT scans may be performed to check for intestinal obstructions, inflammation and abscesses.