Inflammatory bowel disease refers to a group of conditions that cause the lining of your bowel to become inflamed and develop ulcers. The two main types of inflammatory bowel disease are Crohn’s disease and ulcerative colitis. Although the exact cause is unknown, it is likely that a number of different factors are involved. It is currently thought that certain environmental factors may trigger your immune system to attack your bowel, especially if you have a family history of the condition.
Ulcerative colitis affects your large bowel (colon), starting in your back passage (rectum) and spreading upwards. It affects the innermost layer of your large bowel and causes inflammation and sores. How much of the large bowel is affected varies from person to person.
In contrast, Crohn’s disease can affect any part of your bowel and affects several layers of the bowel. It most commonly occurs in the final part of your small bowel (terminal ileum), large bowel and rectum. There is also a tendency for skip lesions; these are areas of your bowel that are unaffected by Crohn’s disease yet sit sandwiched between affected areas.
Inflammatory bowel disease can also affect other parts of your body causing painful joints (arthralgia), sore eyes and skin lesions.
Genetics contribute to both conditions with over 170 genes implicated and significant overlap between the genes involved in each condition. However, there are certain genes and parts of genes that are unique to one condition or the other and may explain some of the differences in the presentation of Crohn’s disease and ulcerative colitis.
When the large bowel is involved, in either Crohn’s disease or ulcerative colitis, you can experience changes to your bowel habits, namely blood-tinged diarrhoea, loose stools, and more sudden and frequent urges to open your bowels. You can also develop cramps, stomach pain, fever, loss of appetite and weight loss.
As both Crohn’s disease and ulcerative colitis can affect the large bowel, it is difficult to diagnose one condition over the other based purely on symptoms.
As symptoms alone are not enough to get a clear diagnosis of inflammatory bowel disease, your doctor will need to take a detailed medical history and carry out several tests. This may include blood tests, stool tests and a colonoscopy to examine the inside or your bowel and collect a tissue sample (biopsy), if needed.
These tests will rule out other causes of your symptoms, such as an infection, help diagnose whether you have Crohn’s disease or ulcerative colitis, and also determine the extent of any inflammation and/or narrowing of your bowel.
In some cases, you may also need to have an imaging test, such as an ultrasound scan, CT scan or MRI scan. This will help your doctor examine areas such as your small intestine and look for changes such as fistulas (abnormal connections between two areas of your body).
When treated and well-controlled, you can enjoy a good quality of life with inflammatory bowel disease. However, if left untreated or poorly controlled, inflammatory bowel disease can lead to several complications, including blood loss, anaemia and nutritional deficiencies. In the long-term, this can increase your risk of bowel cancer.
If you have received a diagnosis of inflammatory bowel disease, it is, therefore, important to attend your review appointments. This allows your doctor to monitor your condition and any changes in your symptoms. As part of this process, you may need to have blood tests, stool tests, imaging tests and when appropriate, a colonoscopy to check the health of your bowel.
Although there is no cure for inflammatory bowel disease, there are a range of treatments that can significantly reduce your symptoms and improve your quality of life.
Medications include drugs to reduce inflammation and prevent flare-ups and drugs to suppress your immune system from attacking your bowel. The particular medication you receive will depend on your symptoms and severity of your condition. In most cases, you will need ongoing treatment to prevent flare-ups.
In addition to medication, your doctor or dietitian may recommend dietary changes and therapies, and/or taking supplements to compensate for nutrients lost due to the inflammation.
If your condition isn’t well-controlled and is affecting your quality of life, your doctor may recommend surgery to remove part of your bowel.
There have been rapid advances in the understanding of what occurs during inflammatory bowel disease at the molecular and genetic level. This is helping develop a more personalised approach to treatment, where medications that target specific molecules can be prescribed based on your individual presentation of the condition.
Developments have also been made in monitoring inflammatory bowel disease with colonoscopies that use artificial intelligence to help identify abnormal areas of tissue.
Improvements in both surveillance and treatment will continue to help improve the quality of life of those with inflammatory bowel disease and reduce the risk of bowel cancer.
Dr Jamal Hayat is a Consultant Gastroenterologist at Spire St Anthony's Hospital and at St George's University Hospitals NHS Trust, specialising in gastroenterology, colonoscopy, endoscopy, gastrointestinal cancer and inflammatory bowel disease. He holds an MD research degree into the use of advanced diagnostic techniques in upper gastrointestinal disease (GI) and continues to participate in multinational research studies. Dr Hayat also runs the GI Physiology lab at St George's Hospital, investigating patients with indigestion and swallowing disorders.
If you're concerned about symptoms you're experiencing or require further information on the subject, talk to a GP or see an expert consultant at your local Spire hospital.