Having a chronic illness may increase the risk of depression, which may in turn make the illness worse. Treating depression has a large effect on your quality of life.
Physical exercise improves confidence and self-esteem and reduces depression and anxiety. It is a good treatment method for mild to moderate depression as it can be recommended to most people and carries no negative social stigmas.
It is important that the exercise is something that you enjoy, has goals, is intensive enough, and is monitored by a health care professional. Both IBD and depression can severely impact your social well-being, which is why it is important that the exercise also provides social contacts. Go for a long walk with a friend, for example, or invite a group of friends for a round of minigolf.
For further reading:
Mälkiä, E. & Rintala, P. (2002). Uusi erityisliikunta. Helsinki: Liikuntatieteellinen Seura ry.