Crohn’s disease is a type of inflammatory bowel disease (IBD). It affects the digestive tract and causes diarrhea, abdominal pain, and weight loss.

Symptoms may appear suddenly, but they can also develop gradually and can worsen over time. They will vary depending on which part of the digestive tract Crohn’s disease is affecting and how severe the condition is.

Experts do not know why Crohn’s disease develops. It may result from an autoimmune reaction, in which the body’s immune system mistakenly attacks healthy cells.

In this article, we examine the signs and symptoms of Crohn’s disease and explain how they can differ depending on the part of the gut in which the condition develops. We also look at diagnosis and when to contact a doctor.

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Crohn’s disease is most likely to appear in people aged 15–30 or 40–60 years. However, it can start at any age.

The symptoms can vary depending on which part of the intestine the condition affects. It usually occurs in the large intestine, or colon. This can lead to the following symptoms:

Common symptomsdiarrhea
unexplained weight loss
stomach pain or cramping
bloating
Other symptomsloss of appetite
anemia
fever
tiredness
eye pain or redness
tender bumps under the skin, of different color than one’s usual skin tone
nausea
joint pain
blood and mucus in stool
Severe or advanced symptomsabscesses
fistulas

If Crohn’s disease affects the small intestine, a person may experience the following:

Common symptomsdiarrhea
malabsorption
weight loss
abdominal pain
low appetite
Severe or advanced symptomsfistulas causing:
urinary tract infections
air bubbles in urine
or feculent vaginal discharge

In children

According to the National Organization for Rare Disorders (NORD), Crohn’s disease in children can lead to:

  • cramping
  • abdominal pain
  • regular episodes of watery diarrhea
  • fatigue
  • fever
  • nausea
  • loss of appetite, which can affect growth and weight gain
  • malnutrition due to a low calorie intake
  • nutritional deficiencies due to malabsorption
  • delayed puberty, in some cases
  • bleeding in the digestive system
  • anemia, which can cause pale skin, faintness, and other health problems

NORD states that around 30% of children with Crohn’s disease develop perianal disease. They may have:

  • abscesses
  • fissures
  • skin tags
  • pain when going to the bathroom

As the condition progresses, a child may experience:

  • obstruction of the large intestine, leading to constipation, cramping, and vomiting
  • lesions in or around the mouth, which affect 40% of children with the condition
  • painful small raised bumps on the skin, of different color than one’s usual skin tone, especially on the shins
  • burning or itching in the eyes due to inflammation
  • joint pain or arthritis

Other conditions and complications

Other signs and complications that commonly occur with Crohn’s disease include:

  • Eye problems: A person may experience eye complications, such as:
    • uveitis, which is a type of inflammation of the eye that causes redness, blurry vision, and sensitivity to light
    • episcleritis, which is inflammation of the inside of the eyelids that can cause pain, burning, itching, and redness
    • scleritis, which causes headaches, light sensitivity, and red eyes, as well as eye pain that worsens upon movement
  • Mouth ulcers: Mouth ulcers can appear when a person has difficulty managing Crohn’s inflammation. Ulcers can develop inside of the lower lip, on the gums, or on the sides of the tongue.
  • Skin tags: These small skin growths typically appear around the anus and can cause skin irritation.
  • Cholangitis: This condition affects the bile ducts and passages from the liver to the small intestine. It can lead to liver damage or failure.
  • Gallstones: Gallstones develop in the gallbladder or bile duct when certain substances harden.
  • Kidney stones: These can form when the urine contains excess calcium, salt, or uric acid, which can crystallize and absorb into the kidneys.
  • Arthritis: This condition typically affects the spine, knees, and hips, among other areas of the body. It can cause pain, swelling, and stiffness.
  • Ankylosing spondylitis: This rare type of arthritis can be severe. It usually develops in the spine and can lead to inflammation of the lungs and heart.
  • Anal fissure: Anal fissures are tears in the anus lining that can cause bleeding with bowel movements.
  • Malnutrition: When Crohn’s disease causes malnutrition, it is because the small intestine cannot absorb nutrients efficiently.
  • Fistula: This type of ulcer forms at the openings of the intestines. It can also develop in the bladder or vagina.
  • Strictures: These thick and narrow parts of the intestines may result in bloating, cramping, and stomach pain.
  • Bone loss: A person with Crohn’s disease may experience bone loss due to chronic inflammation. It may also be a side effect of medications a person is taking for the condition.
  • Pancreatitis: This is inflammation of the pancreas. It may cause a fever, nausea, vomiting, and pain.
  • Slower physical development: Children with Crohn’s disease may be shorter and weigh less than they would without the condition. They may also experience delayed puberty.

Symptoms worsen during a flare-up and improve in times of remission. Stress and certain foods may trigger or worsen symptoms.

People should seek guidance from a doctor if they experience any of the following symptoms:

  • diarrhea that lasts for 7 days or longer
  • frequent stomach pain, cramping, and discomfort
  • blood in stool
  • unexplained weight loss

A doctor will usually start by asking about signs and symptoms. However, the most common symptoms of Crohn’s disease can also occur with other conditions.

For this reason, the doctor will likely order various tests to determine whether a person’s symptoms are due to Crohn’s disease.

The doctor may:

  • ask about pain and other symptoms
  • take a personal and family medical history
  • carry out a physical examination

In addition, they may recommend some of the following tests:

They may also recommend colonoscopy, which involves inserting a thin, flexible tube into the digestive tract through the anus. The tube has a light and camera on it and enables the doctor to see what is happening inside the gut.

People may often mistake the early symptoms of Crohn’s disease for those of other conditions, such as:

It is best to contact a healthcare professional if symptoms persist for more than 2 weeks. A doctor can look for the cause of the problem and recommend suitable treatment.

There are five types of Crohn’s disease, and they differ according to the part of the digestive tract they affect. They also manifest slightly differently, which helps doctors diagnose the type of the condition correctly.

Below is an overview of each of the five types of Crohn’s disease and their symptoms.

Learn more about the types of Crohn’s disease here.

Ileocolitis

Ileocolitis is the most common type of the condition. It affects the large intestine and the end of the small intestine.

Common symptoms are:

  • pain or cramping in the center or lower right region of the abdomen
  • diarrhea
  • sudden, unexplained weight loss

Ileitis

Ileitis affects the ileum, which is the narrowest and final section of the small intestine.

Its symptoms resemble those of ileocolitis, but complications can arise. These include fistulas or abscesses in the lower right part of the abdomen.

A fistula in the gut is a passage that develops between the digestive tract and another part of the body.

Crohn’s colitis

Crohn’s colitis, or granulomatous colitis, only affects the large intestine.

Typical symptoms include:

  • ulcers, fistulas, and abscesses around the anus
  • joint pain
  • skin changes
  • diarrhea
  • bleeding from the rectum

Gastroduodenal Crohn’s disease

With gastroduodenal Crohn’s disease, severe inflammation occurs in the stomach and the first part of the small intestine.

Symptoms include:

  • loss of appetite
  • weight loss
  • nausea
  • vomiting

Jejunoileitis

This type of the condition affects the upper half of the small intestine, called the jejunum.

Symptoms include:

  • diarrhea
  • stomach cramping or discomfort after eating
  • fistulas, in severe cases

Crohn’s disease and ulcerative colitis (UC) are both types of IBD. Irritable bowel syndrome (IBS) and celiac disease can produce similar symptoms as well.

The table below lists some of the similarities and differences between these different conditions.

Crohn’s diseaseUCIBSCeliac disease
Ageany, but especially 15–30 and 50–70 yearsany, but especially 15–30 and 40–60 yearsany, but especially in the youngany, but especially 30s-40s
Sexanyanyparticularly in femalestwice as common in females
Area affectedcolonany part of the digestive tractcolonsmall intestine
Common symptomsdiarrhea and bleedingpain
diarrhea
weight loss
diarrhea and constipation
bloating
abdominal pain and cramping relieved by defecation
diarrhea and other symptoms, depending on age at start
Risk factorssmokinggenetic factorspsychological stresshaving another condition, particularly an autoimmune disorder

Learn how Crohn’s disease compares with other digestive disorders here.

There is no cure for Crohn’s disease, but people can make certain lifestyle changes and take medications to alleviate symptoms and manage the condition.

Depending on the type of Crohn’s disease, the severity of symptoms, and a person’s medical history, doctors may recommend one or more of the following treatment options:

  • steroids or other drugs to reduce inflammation
  • antidiarrheal medication to treat mild diarrhea
  • sulfasalazine to manage mild symptoms
  • surgery to remove a part of the stomach or intestine
  • antibiotics to destroy any bacteria that may cause infection
  • draining any abscesses
  • biologics, such as anti-tumor necrosis factor (anti-TNF) agents and anti-integrin agents

Biologic drugs can help manage and prevent flares by influencing the way the immune system works.

Examples of anti-TNF agents include:

Anti-integrin agents for Crohn’s disease include natalizumab (Tysabri) and vedolizumab (Entyvio).

Dietary tips

The National Institute of Diabetes and Digestive and Kidney Diseases suggests making some dietary changes to help reduce the symptoms of Crohn’s disease, including:

  • avoiding fizzy drinks
  • avoiding high fiber foods, such as popcorn
  • drinking more liquids
  • eating small, frequent meals
  • keeping a food diary to help identify triggers

Other lifestyle measures

Apart from diet, the following lifestyle tips may help manage Crohn’s disease:

Prevention

As experts do not fully understand the cause of Crohn’s disease, they cannot recommend any specific way to prevent it. However, the following may help:

The early signs and symptoms of Crohn’s disease can resemble those of other conditions.

Anyone who notices new and persistent gastrointestinal symptoms should seek medical attention. Early treatment can help address symptoms and prevent flares and complications.

Most people with Crohn’s disease will need lifelong treatment. Maintaining contact with a medical team and following a treatment plan can help a person manage their symptoms and improve their quality of life.

Having support from others who understand the experience of having the condition can also help. IBD Healthline is a free app for people with IBD, including Crohn’s disease. The app is available on the App Store and Google Play. Download here: https://go.onelink.me/LOC7/cfbeaeec.

Read the article in Spanish here.