That author is absolutely correct. Fasting can definitely help with UC, it heals your body but most importantly it heals your stomach and liver, which directly affect your digestion and UC. Fasting with only distilled water is maybe the best way, but it needs to followed up with a diet. You don't have to be as radical as 6 weeks (7-10 days is plenty). I highly recommend reading about fasting before doing one. Fasting is great, if done properly and with some knowledge.
After the fast, it's important to change your diet to at least remove foods that are not good for you, or you could be in the same situation months down the road. Or... have other problems.