Inflammatory bowel disease (IBD) is a term that describes disorders that involve a chronic (persistent) inflammation of the digestive system. This can cause symptoms including diarrhoea, rectal bleeding, stomach pain, fatigue and weight loss.(1) IBD commonly refers to two disorders – Crohn’s disease and ulcerative colitis.
What is the difference?
The two share common symptoms but there are some key differences:
Crohn’s Disease
Crohn’s can affect any part of the digestive system. It appears as inflammation, sporadically, with healthy areas between the inflamed spots.(2) Crohn’s is often marked by nausea, weight loss, vomiting and anal bleeding with other symptoms including mouth sores or inflammation of the eyes, joints and skin.(3)
Ulcerative Colitis (UC)
While Crohn’s may affect any part of the digestive system, children who develop UC are affected by sores, which appear only in the inner most lining of the large intestine and rectum. Tell-tale signs of UC include blood in stool with mucus, diarrhoea and tenesmus, the sensation of needing to go to the toilet but without having a bowel movement.(3)
What causes IBD?
Our bodies protect us from harmful substances such as viruses and bacteria by recognising proteins on these foreign bodies called antigens. When our bodies detect antigens somewhere they shouldn’t be, our immune system will attack and destroy them to keep us safe.(4)
However, our digestive system is constantly exposed to new antigens that are found in bacteria and the food we eat, so our bodies tell our immune system not to worry about the antigens in our gut because they’re allowed to be there. This is called “gut homeostasis”.(5)
Your genes might also play a role in the likelihood of you developing IBD(1)
We don’t fully understand why,
but in a person with IBD, their body does not understand that it’s fine for the foreign bodies to be in their digestive system and instead tries to fight them off. This is what causes inflammation of the gut and the other consequential symptoms such as bleeding and weight loss.(6)