Crohn’s disease and its complications can affect any area of the digestive tract from the mouth to the anus.
If you have severe Crohn’s disease or do not receive effective treatment, you may experience severe complications.
This article discusses possible Crohn’s disease complications, including symptoms to look out for and when to see a doctor.
Strictures and obstruction
Inflammation due to Crohn’s disease can cause scar tissue to build up. A stricture is when this scar tissue fuses together and narrows the bowel.
In some cases, a stricture can lead to an obstruction, whereby your intestines become blocked off.
Learn more about the symptoms, causes, and treatment of strictures and obstructions.
A fistula is when a passageway or connection forms between two areas.
For example, with Crohn’s disease, you may develop a tunnel connecting the lining of the rectum and the skin around the anus. This is known as a perianal fistula.
Symptoms of fistulas depend on what body parts they involve, for example:
- A fistula between the bladder and intestines can lead to a urinary tract infection.
- A fistula connecting to the vagina can lead to gas or stool passing through the vagina.
- A fistula linked to the skin can appear as a painful bump or abscess that leaks fluid or stool.
Read more about gastrointestinal and anal fistulas.
Perforations are tears or holes in the intestinal walls. They develop when the intestinal walls are weakened due to:
- strictures or obstructions
- ulcers
- fistulas
- abscesses
- intestinal surgery
Perforations can be life threatening, as bacteria from your intestine can spill into your stomach and cause a serious infection known as peritonitis.
Learn more about the symptoms, risk factors, and treatment of intestinal perforations.
Some complications, such as fistulas or perforations, can lead to infections and abscesses.
An abscess is a buildup of pus. If it is close to the outside of the body, you may feel a painful or tender lump. However, abscesses can develop anywhere in the body, including internally.
Without treatment, abscesses can damage the surrounding organs.
See more about abscesses, including symptoms, pictures, and treatment.
Rarely, Crohn’s disease causes toxic megacolon, whereby the colon expands beyond its usual size.
Toxic megacolon can be life threatening, as it means the colon cannot contract properly. This causes gas to buildup, which may lead to:
- the colon bursting and leaking bacteria and toxins into the blood
- sepsis
- internal bleeding
Symptoms of toxic megacolon include:
- fever
- fast heart rate
- dehydration
- nausea and vomiting
- diarrhea, which may contain blood
- shock, which can cause:
- a weak pulse
- cool or clammy skin
- dilated pupils
- shallow or fast breathing
- changes in mental status, such as confusion or loss of consciousness
Call 911 or seek emergency medical care for any toxic megacolon symptoms.
Learn more about toxic megacolon.
Having Crohn’s disease raises your risk of developing:
Learn more about skin cancer symptoms and prevention.
However, effective Crohn’s disease treatment may help reduce the risk of cancer.
Colorectal cancer doesn’t always cause symptoms. Also, some colorectal cancer symptoms — like diarrhea and constipation — can be confused for typical Crohn’s disease traits.
Getting a colonoscopy every 1 to 2 years can help spot cancer early, possibly improving outcomes.
Read more about colorectal cancer and lymphoma, including their symptoms and prevention.
Crohn’s disease commonly causes malnutrition due to several factors:
- Bleeding from intestinal ulcers can cause iron deficiency and anemia.
- Symptoms like stomach pain, nausea, and frequent bowel movements may reduce your motivation to eat.
- Severe diarrhea may cause dehydration and loss of essential nutrients.
Symptoms of malnutrition vary depending on the nutrient deficiency but can include:
- weight loss
- decreased appetite
- constant tiredness or feelings of being cold
- weakness
- frequent illness
- long recovery times from illness
- wounds taking longer to heal
- difficulty concentrating
- low mood or depression
- in children, symptoms such as:
- slow growth or lack of weight gain
- changes in behavior, such as increased irritability or anxiousness
- low energy compared to other children
Sometimes inflammation from Crohn’s disease can also affect the eyes, leading to conditions such as:
- scleritis, inflammation of the white of the eye, known as the sclera
- episcleritis, inflammation of the tissue between the eye’s outer layer and sclera
- uveitis, inflammation of the layer of tissue underneath the sclera
- keratopathy, conditions that affect the eye’s cornea
- dry eye, whereby your eyes do not produce enough tears
Read more about how Crohn’s disease can affect your eyes.
Crohn’s disease may be linked to a higher risk of acute and chronic kidney disease.
With Crohn’s disease, one of the most common kidney complications is kidney stones. These are hard, stone-like deposits that form inside the kidney and can block key passageways.
Read more about acute and chronic kidney disease and kidney stones.
Crohn’s disease inflammation and medications can affect the function of the liver. This increases the risk of complications, including:
- fatty liver disease, whereby fat cells build up in the liver
- hepatitis, inflammation of the liver
- gallstones, whereby hard, stone-like deposits form within the gallbladder
- sclerosing cholangitis, inflammation in the bile ducts inside and outside the liver
Crohn’s disease can lead to many different skin disorders, such as:
- erythema nodosum, inflamed lumps under the skin
- pyoderma gangrenosum, a type of painful skin ulcer
- skin tags, growths on the skin that are usually harmless
- canker sores, a type of mouth ulcer
- vasculitis, inflammation of the blood vessels
Learn more about Crohn’s disease-related skin disorders and rashes.
Other possible complications
Other Crohn’s disease complications include:
- Mental health conditions: Crohn’s disease may contribute to mental health conditions such as anxiety and depression. This may be due to the impact of managing a chronic condition and how it affects your quality of life.
- Osteoporosis: Osteoporosis is when the bones weaken, increasing the risk of fractures. In Crohn’s disease, osteoporosis may develop due to inflammation, long-term steroid use, and malnutrition.
- Arthritis: Crohn’s disease can cause different types of joint inflammation and arthritis, such as axial spondyloarthritis.
Learn more about Crohn’s disease and joint pain.
If you have Crohn’s disease, contact a doctor as soon as possible for any new, persistent, or changing symptoms.
Some Crohn’s disease complications are a medical emergency and require immediate care. Call 911 for symptoms such as:
- blood in your vomit
- blood in your diarrhea or coming from your anus
- severe or persistent pain or diarrhea
- unexplained weight loss
- fever that lasts more than 2 days
- toxic megacolon symptoms
If you are unsure of whether to visit a doctor or a hospital, contact your local health center for advice.
Also talk with your medical team if you have any questions about Crohn’s disease, including its diagnosis, treatment, or complications.
Crohn’s disease can lead to various complications, such as:
- malnutrition
- intestinal blockages or perforations
- fistulas
- toxic megacolon
- increased risk of cancer
- skin disorders
- kidney stones
- liver disease
- eye inflammation
Contact a doctor as soon as possible for any new, concerning, or changing symptoms. Treatment can help reduce the risk of complications or improve your outcome.