May 19 is “World IBD Day.” Inflammatory bowel disease (IBD) is an incurable autoimmune disease characterized by diarrhea, bloody stools, and abdominal pain. Although the number of patients in Korea was small enough to fall into the category of rare diseases in the past, the number of patients in 2022 was about 86,000, far exceeding the threshold of 20,000 for rare diseases in Korea, and the number is increasing every year.

Inflammatory bowel diseases are mainly divided into ulcerative colitis and Crohn's disease; of which Crohn's disease, which is characterized by recurrent abdominal pain and diarrhea, is often mistaken for irritable bowel syndrome (IBS) in young people, leading to late diagnosis.

Korea Biomedical Review met with Dr. Ko Seong-joon, a professor of gastroenterology at Seoul National University Hospital, to learn about IBD and how early diagnosis can improve treatment.

Question: What is inflammatory bowel disease?

Answer: Inflammatory bowel disease is an unexplained inflammatory response in the intestines that persists for a long time, causing symptoms including abdominal pain, diarrhea, and bloody stools. There are two main types: ulcerative colitis and Crohn's disease. In the past, the incidence of inflammatory bowel disease was high in Western countries, but in the last decade, it has been increasing rapidly in Korea.

Q: What causes IBD?

A: There’s still no clear cause of IBD. It is thought to be caused by a combination of genetic factors, gut microbiota, and various environmental factors, including diet, medications, and smoking.

Primary immediate family members of patients IBD are at about 20 times increased risk than the general population. People with immune disorders, such as ankylosing spondylitis, psoriasis, and uveitis, have also been reported to have a higher risk of developing IBD, ranging from several times to dozens of times higher.

Q: IBD is divided into ulcerative colitis and Crohn's disease. How do you tell the difference, and what are the symptoms of each?

A: Ulcerative colitis is when inflammation only affects the large intestine. The main symptoms include bloody stools, diarrhea, and mucous stools. Some patients undergo surgery for uncontrolled inflammation, and the longer the inflammation is present, the higher the risk of developing serious complications, such as colon cancer.

Ulcerative colitis is most commonly seen in people in their 20s and 40s, but in recent years, the number of cases has been increasing rapidly in people over the age of 60. Because ulcerative colitis is mainly inflamed in the shallow layers of the mucous membrane, complications, such as strictures and perforations, are less common than in people with Crohn's disease.

Unlike ulcerative colitis, Crohn's disease involves inflammation throughout the entire digestive system, from the mouth to the anus. Because the inflammation is deep and involves all layers of the intestine, endoscopy can reveal deep ulcers and complications, including strictures, abscesses, perforations, and fistulas, which can easily occur. The disease is most common in people between the ages of 10 and 20, and genetic factors are thought to play a role in its development.

Abdominal pain and diarrhea are common, but these symptoms can be taken lightly because they are similar to those of irritable bowel syndrome (IBS). They may also improve without specific treatment, leading to a delayed diagnosis or diagnosis after complications have developed.

Crohn's disease should be suspected if you have recurrent abdominal pain and diarrhea at a young age, accompanied by weight loss; if you have had previous treatment for fistulas, dental or perianal abscesses; if you have a family history of inflammatory bowel disease; or if you have an autoimmune disease such as psoriasis or ankylosing spondylitis.

Q: How are inflammatory bowel diseases diagnosed?

A: Crohn's disease and ulcerative colitis can be diagnosed if a person has chronic digestive symptoms and has characteristic findings on colonoscopy or if chronic inflammation is confirmed after biopsy. Ulcerative colitis is diagnosed through a colonoscopy, which is recommended for patients who have diarrhea for more than four weeks, bloody or mucous stools, or perianal abscesses.

Recently, a stool test called calprotectin became available. It measures a substance called calprotectin. If the calprotectin test is normal, the likelihood of ulcerative colitis is very low. Therefore, it can be used as a simple screening test without requiring a colonoscopy in all patients.

On the other hand, Crohn's disease is characterized by small bowel involvement, so in addition to colonoscopy, the small bowel should also be evaluated with CT or MRI. About 80 percent of cases of Crohn's disease are diagnosed without complications at the time of diagnosis, while the rest are diagnosed with complications, such as strictures or abscesses.

Q: What are the treatments?

A: The main treatment for inflammatory bowel disease is medication. The main goals of treatment are to eliminate symptoms and prevent long-term complications, such as perforations, strictures, and colon cancer. Medication helps to repair the damaged intestinal mucosa and reduces the level of inflammation, which helps to reduce the risk of surgery.

If the inflammation is limited in scope and not severe, the anti-inflammatory drug 5-ASA is taken orally or injected into the anus. If the inflammation is widespread and severe, steroid medications to modulate the immune system or immunosuppressive drugs, such as azathioprine, are used. Biologics or small molecule drugs are used if these drugs are ineffective or have side effects.

If medications don’t work or complications, such as strictures, perforations, or colon cancer, occur, surgery may be considered. For ulcerative colitis, surgery usually involves removing the entire colon, and for Crohn's disease, surgery involves cutting out a small section of the inflamed area. Surgery is highly curative because it removes all of the inflamed areas, but it can cause a lot of discomfort in daily life.

Q: What should people do if they have symptoms of IBD or are at high risk for IBD?

A: If you have symptoms, such as diarrhea, bloody stools, recurrent abdominal pain, or weight loss, it's a good idea to see an IBD specialist. In addition, high-risk groups, including siblings and children of people with inflammatory bowel disease, have about a 20-fold increased risk of developing the disease, so a yearly calprotectin test, even if you don't have symptoms, can help with early diagnosis.

Use antibiotics or anti-inflammatory painkillers only when necessary and avoid long-term use. Avoid foods that are too salty or sugary, which can trigger inflammation in the gut, and eat a high-fiber diet to help build a healthy gut microbiome.

Also, eat proteins, including fish, rather than red meat, such as pork or beef, which can trigger an inflammatory response. Regular aerobic exercise, getting enough sleep, and owning a pet also contribute to a healthy gut microbiome.

Q: What advice do you have for people living with IBD?

A: Inflammatory bowel disease is an incurable disease, so long-term management and prevention of potentially fatal complications, such as perforation, abscesses, and colon cancer, are important. It is important to realize that if diagnosed early enough and the inflammation is properly managed with medication, it is possible to live a normal life with no complications.