Our body is a special machine. Every time we are hurt in someway, have injuries or a damage, it tries to recover by itself. In some cases we have to help it, for self curing.
Recovery and Rehabilitation from Chronic Diseases is also one of our body's virtues. When suffering from a chronic disease, such as Ulcerative colitis, IBS, the body knows how to handle the situation, and by giving the body's fuel, e.g. food, good sleep, relaxing, sports and so, it starts to get over the disease.
Controlling the fuel may cause a better treatment. For example, changing to a better food, upgrading the sleeping conditions, doing some relaxing sports, such as Yoga. All of these gives the body a greater power for self healing.
Help your body help itself.