Painful but uncommon injuries that develop most frequently in people with chronic intestinal disorders, such as Crohn’s disease, anal fistulas usually require surgery to heal. An anal fistula forms an abnormal channel between the anal canal and the skin near the anus, often following an intestinal infection or abscess in the anus. Surgery to drain the abscess, called a fistulotomy, allows the infection to heal and the abnormal channel to close. After anal fistulotomy, the right diet can help prevent complications.
You may experience mild to moderate pain for up to a week after a fistulotomy. If you experience pain, you may try to avoid passing stool, which can lead to more severe constipation. Keeping stools soft and bulky helps them move easily through the gastrointestinal tract. Pain medication used after surgery can also have constipating effects. Your doctor may also prescribe laxatives or stool softeners after surgery.
Following a high-fiber diet after surgery bulks up the stools and also keeps them soft by drawing water into the stool from the intestine. High-fiber foods include fruits and vegetables as well as whole grains. Eat four servings of fruits and vegetables and four servings of cereal and other whole grains to prevent constipation. Keeping the skin on fruits and vegetables provides extra fiber. Fiber in wheat and oat bran may be more effective in preventing constipation than fruits and vegetables. Try to include at least 20 g of fiber if you’re female and 30 to 35 g if you’re male.
You must increase your fluid intake when you increase your fiber intake, or stools could become large and hard. Intestinal blockage, a potentially serious complication, can occur if stool can’t pass. Drink at least eight to 10 8-oz. glasses of fluid during the day to keep stools soft. Avoid drinks that contain caffeine, which can worsen constipation, because caffeine has a dehydrating effect.
If you become constipated after surgery, you can easily retear an anal fissure. Complete healing may take several weeks, so take care to keep stools soft. Anal fissures can also recur, so make high-fiber foods and extra fluid part of your normal diet. Increased pain and rectal bleeding may indicate a new fissure. Increase your fiber intake slowly, or you could develop uncomfortable abdominal distention and gas.