I have done one 39 day master cleanse (Nov 2003) and one 9 day water only fast (Jan 2004). I would have loved to continue the Water Fast but I developed a very bad sore/dry mouth and throat and I concluded that it was too stressful for my body since The Master Cleanse was not even 2 months past. A good way to 'ramp' up to Water Fasting may be a short 2 or 3 day fast. However, for myself and many others, most of the discomfort and any agonizing food cravings do occur in the first few days. By day 7, 8, and 9 I was very prepared psychologically to continue the fasting.
I would imagine the nature of and degree of your illness would also have an effect on how long you would fast, what your energy levels would be like and so forth. I was in very good general health (was fasting for weight loss) so my energy levels were enough to continue working my part time job and housewife chores. Most experts do not recommend undergoing extended fasts beyond 10 days (some say as little as 3) without some kind of medical supervision.
Here is a list of possible side effects (this is taken from the 'Informed Consent' link off the fasting link on the True North website.
"There are many risks to water-only fasting and we want you to be aware of them prior to your decision to undertake a water-only fast. Because you will not be eating any food, you will most certainly experience weakness throughout the water fast, and lose weight. It can take some time after fasting to regain strength. A very common occurrence is dizziness and fainting, especially on rising from a laying or seating position. Other common and unpleasant symptoms are heart arrhythmia, palpitations, dehydration, nausea, vomiting, skin rashes, sore throat, mucus discharge, low back pain, increased menstrual flow, irregular or anovulatory cycles, hair loss, gastric irritation, passing of kidney or gall stones and emotional disturbances. There is also the possibility of alterations to your body’s basic mechanisms and electrolytes, which could cause heart problems such as a heart attack or vascular problems such as a stroke".
I didnt have any trouble with skin conditions, Body Odor s or urine levels and I was surprised at how many bowel movements I had during that 9 days. I had about 5. I lost 21 pounds as well.
The Fasting and Eating for Health book by Fuhrman is an excellent resource and I read it twice. I would recommend educating yourself a bit before attempting a longer fast. But the enhancement to your health could be monumental and I pray you will be rewarded for your efforts. My husband has Rheumatoid Arthritis and I keep hoping he will respect/respond to these fasting and nutritional therapies.
Good hope to you on your journey to health! Keep us posted of your progress.