Complications of Crohn's Disease

Medically Reviewed by Brunilda Nazario, MD on October 30, 2023
5 min read

Crohn’s disease can cause symptoms throughout your body. But this condition can affect everyone differently. Here are some common complications.

This includes organs and parts of your body that help turn food and drinks into energy. It starts in your mouth and stretches down to your anus. Many symptoms of Crohn’s disease can happen within your bowel, the lower part of your digestive system.

Stricture. This is when a part of your intestine gets too narrow. It can happen because of scar tissue from repeated inflammation. Severe stricture can eventually cause your digestive tract to shrink inward.

That could lead to blockages in your bowel. You might have stomach pain, bloating, nausea, or have trouble pooping. Your doctor may order a colonoscopy, MRI, or CT scan to diagnose a stricture. Your treatment may be simple, or you might need surgery.

Fissure. It means a small rip in the tissue. You might get a fissure around your anus or the skin around your butt. That can hurt for several hours after you go to the bathroom. You might see blood in your poop. You also may notice a bump on the skin around the tear.

Anal fissures from Crohn’s most often appear on the side of your anus, instead of the back or front. Your doctor will usually be able to diagnose your anal fissure after a quick look around the area.

You may heal your fissure in a few weeks by drinking more fluids and eating more fiber. If home remedies don’t help, your doctor can treat it, including with surgery.

Fistula. Crohn’s disease may cause an open sore called ulcer in your digestive tract. These can expand into your intestinal wall and form a fistula, a tunnel that forms where it shouldn’t. This channel can connect your intestine to skin near your anus, or in other parts of your body.

Based on where they occur, fistulas can mess with your body’s normal digestive process. In some cases, fistulas may become infected which could be deadly if you don’t get treatment.

Abscess. This is a buildup of pus. You can get an abscess in your abdomen or anal area. It can make pooping uncomfortable. Your belly might hurt and you might run a fever. You also may notice a lump or a discharge of pus from your butt.

You may need antibiotics and possibly surgery. Your doctor will make a small cut in the abscess to drain the pus. This will help the area heal normally.

Bowel obstruction. This is when sections of your bowel get narrower and scarred over time. That can block your intestines and lead to stomach cramps, lack of appetite, constipation, stomach inflammation, or nausea.

An obstructed bowel may require surgery to take out the affected part of your bowel.

Malnutrition. The diarrhea, stomach cramps, or pain from Crohn’s may make eating difficult. Your intestine may not absorb enough nutrients your body needs. You may run low on vitamins and minerals such as iron or vitamin B-12.

To avoid malnutrition, it’s important to keep a healthy diet. But it is also important to watch for foods that make your Crohn’s flare up. Talk to you doctor about best foods for you, and if you need any supplements.

Perforated bowel. If your bowel is weakened from fistula or an abscess, your intestinal wall may tear. That can spill harmful bacteria-laden content into your stomach. A perforated bowel can be deadly.

If your bowel rips, you may have chills, a fever, nausea, intense stomach pain, or go into shock. Your doctor can use an X-ray or CT scan to find the hole. A procedure called an endoscopy or colonoscopy also may help them find the exact location of the tear.

Usually, you’ll need an emergency surgery. Your doctor may need to take out part of your intestine and drain your abdomen and any other involved organs. The hole may close on its own. But that’s rare.

Colon cancer. If your Crohn’s disease affects your colon, the inflammation can raise your chance for cancer there. The overall risk of colon cancer from Crohn’s is low. Sticking to your treatment plan, exercise, and a healthy diet can help prevent it. Tell your doctor of any changes in your health or if a family member gets colon cancer.

Crohn’s disease may lead to complications in many other parts of your body.

Arthritis. Around 3 out of 10 people with Crohn’s disease get this. Arthritis is the most common Crohn’s complication outside of your bowel.

People usually use nonsteroidal anti-inflammatory drugs (NSAIDs) for arthritis pain. But these might not be safe if you have Crohn’s because they may irritate the lining of your intestines and worsen your symptoms.

Your doctor may put you on non-NSAID medications for your arthritis. Physical therapy and moist heat on your joints also may help.

Skin disorders. This is the second most common Crohn’s issue outside of your bowel. About 20% of people with Crohn’s also have skin problems. There are many types of disorders related to Crohn’s, so it’s important to visit your doctor if you have any new skin issues.

Eye inflammation. This happens in about 1 in 10 people with Crohn’s. But most of them are easily treatable and won’t damage your vision seriously. Stay on top of your eye exams and always tell your doctor about any eyesight changes.

Osteoporosis. You may get this bone-thinning disease if Crohn’s prevents your body from absorbing enough vitamin D and calcium. Inflammation and steroid use from Crohn’s may also lead to osteoporosis.

Liver disease. Your liver could become inflamed from Crohn’s disease, but most damage is fixable. Only about 5% of people with Crohn’s will have severe liver complications. If you have Crohn’s, it’s a good idea to have your doctor check your liver regularly.

Kidney disorders. Severe kidney disorders are rare with Crohn’s disease. Kidney stones are the most common complication due to lack of fat absorption or dehydration. It’s a good idea to drink more water to avoid kidney issues.

Anemia. About 1 in 3 people with Crohn’s get anemia, which is when you lack healthy red blood cells. Anemia can result from lack of iron. It can make you feel tired, dizzy, and short of breath. Other symptoms of anemia may include headache, get cold hands and feet, and pale skin.