Symptoms depend on what part of the gastrointestinal tract is affected. Symptoms range from mild to severe, and can come and go with periods of flare-ups.

The main symptoms of Crohn's disease are:

• Crampy abdominal (belly area) pain
• Fever
• Fatigue
• Loss of appetite
• Pain with passing stool (tenesmus)
• Persistent, watery diarrhea
• Unintentional weight loss

Other symptoms may include:

• Constipation
• Eye inflammation
• Fistulas (usually around the rectal area, may cause draining of pus, mucus, or stools)
• Joint pain
• Liver inflammation
• Mouth ulcers
• Rectal bleeding and bloody stools
• Skin rash
• Swollen gums

A physical examination may reveal an abdominal mass or tenderness, skin rash, swollen joints, or mouth ulcers. Tests to diagnose Crohn's disease include:

• Barium enema
• Colonoscopy
• Computed tomography (CT scan) of the abdomen
• Endoscopy, including capsule endoscopy
• Magnetic resonance imaging (MRI) of the abdomen
• Sigmoidoscopy
• Enteroscopy
• Upper GI series

A stool culture may be done to rule out other possible causes of the symptoms.

This disease may also alter the results of the following tests:

• Albumin
• C-reactive protein
• Erythrocyte sedimentation rate
• Fecal fat
• Hemoglobin
• Liver function tests
• White blood cell count