A diet that includes raw fruits, vegetables and nuts may reduce the symptoms of an anal fistula and promote wound healing. Bowel movements can cause severe pain with an anal fistula, especially if digestive wastes are hard and difficult to pass. A diet for anal fistula should emphasize nutritious high-fiber foods that ease bowel movements and support the formation of healthy new tissue.

Causes

A bacterial infection is often the underlying cause of an anal fistula, an abnormal, tunnel-like opening leading from the anus to the skin surrounding the anus or to an internal organ. A bacterial infection in the anus or rectum may cause an abscess, or a pocket of pus, to form. If the abscess ruptures, the underlying wound may form a fistula. An anal fistula may cause pain and irritation around the rectum and anus and may trigger a fever as your body fights the infection. People with Crohn’s disease, a chronic inflammatory bowel condition that can damage the tissues of the digestive tract, are prone to developing anal fistulas. Colorectal cancer, diverticulitis, an anal or rectal injury, or radiation treatment may also cause an anal fistula.

Treatment

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University of Iowa Health Care recommends a high-fiber diet as part of a comprehensive treatment program for anal fistula 2. Fiber bulks up stool and makes bowel movements easier to pass, reducing strain on the anal sphincter and preventing painful constipation. Drinking water and other noncaffeinated fluids throughout the day will soften stool and ease bowel movements. Your health care provider may advise adding psyllium seed or another natural fiber supplement to your diet to promote bowel activity and soften digestive wastes. A comprehensive treatment plan may also include warm sitz baths and suppositories or ointments to minimize pain and inflammation. Surgery may be required if the fistula does not heal promptly.

Nutritional Benefits

Vegetables, fruits and nuts offer vitamins and minerals that support your immune system and speed wound healing. Beta carotene, a plant-based compound found in orange, yellow, red vegetables and fruits and in green leafy vegetables, converts to vitamin A when food is digested. Vitamin A supports the integrity of the skin and the tissues that line body cavities. Vitamin C, found in citrus fruits, tomatoes and many other fruits and vegetables, boosts the immune system and helps your body resist infection. Almonds, cashew nuts and peanuts contain zinc, a mineral that contributes to new cell formation and wound healing. Raw produce retains a higher amount of water-soluble nutrients, such as vitamins B and C, than do cooked fruits and vegetables. However, unless you have a preference for raw food, eating baked, steamed or roasted foods that are high in fiber may be equally beneficial for healthy digestion and wound healing.

Precautions

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While a diet that emphasizes raw food may help an anal fistula heal, high-fiber foods may worsen symptoms in people with Crohn’s disease, the University of Maryland Medical Center notes 3. Steamed, baked or boiled vegetables and fruits may be easier to digest if eating raw foods causes gas, indigestion, bloating or abdominal pain. Some nutritious foods can increase your risk of a foodborne illness when eaten raw. While shellfish is high in zinc, a mineral that promotes wound healing, raw shellfish may contain harmful bacteria and parasites. Talk with your health care provider or a nutritionist about a diet that will meet your nutritional needs while promoting healing of an anal fistula.