Fat

• Reduce fat in your diet. Fatty foods have long been known to be bad for digestive health. Dietary fats do not easily break down in the stomach and can lead to undigested portions of food. In order for the colon to get cured as quickly as possible, it needs to be in complete working order. Since fats don't digest properly, it can lead to a further inflammation of the colon making it difficult for the colitis to clear up.
  
  

Caffeine

• Another major factor in the fight against your colitis is caffeine and lactose. Caffeine is a diuretic, which causes water to leave your body at an increased rate, making you prone to dehydration. If you are dehydrated, your body will not be able to help heal itself. Also, caffeine stimulates your gastrointestinal tract to overactivity, which produces a laxative effect increasing the presence of stool in the colon and irritating it further. It is also highly acidic, which can irritate the stomach and produce an overabundance of stomach acid.
  
  

Other Foods

• Avoid spicy foods, as they can irritate the stomach and cause further damage to an already irritated colon. Also, try to stay away from alcohol; it is also a diuretic and acts to depress your gastrointestinal tract. This will slow down the natural metabolism needed for good intestinal health. Cut back on foods that contribute to diarrhea and gas, such as leafy green vegetables and raw fruits, to keep from putting further strain on an already damaged area.
  
  Doctors recommend staying away from any products that contain lactose, the sugar which is found in milk and milk products. If you are already lactose intolerant, the presence of lactose may negatively affect the healing process of the colitis, and the colitis might actually make the intolerance worse. If you don't have an existing lactose intolerance condition, colitis may cause one if there is lactose present in a damaged colon.