That is a long time to have "ulcerative colitis".
I am assumimg that he has seen his doctor with little success.
I have 4 dietary modifications for him:
1. Drink plenty of liquids to prevent fluid and elctrolyte imbalance. When drinking fruit juices ( Carrot or cabbage ), mix half and half with pure water or Aloe Vera juice. 1/2 cup in the morning and at bedtime.
2. Eliminate all solid foods. Liquid diets consisting of fresh fruit and vegetable juices provide nutrients and give your bowel a rest. To increase protein intake make a smoothie with a banana or other fresh fruit. Vegetable soups and steamed vegetables can be liquified by using a blender or a juicer. Use NO butter, milk or sour cream. This bland and primarily liquid diet should be followed for about two weeks for best results.
3. After that, a low fiber, bland, high protein, high calorie should be eaten in six small meals a day. Avoid dairy products, processed foods, fried foods and coffee.
4. Take a high potency liquid vitamin and mineral supplement and an effective digestive enzyme product. Deficiencies of the following nutrients have been found in hospitalized patients with colitis: Vitamin A, C, K, Zinc and Folic Acid.