The digestive system is responsible for breaking down food into nutrients that can be absorbed by the body for fuel, growth and cell repair. Good nutrition is essential for maintaining proper function of the body’s systems.

Eating a well-balanced, nutritious diet and maintaining healthy habits are the best ways to prevent digestive problems. Generally, health experts recommend the following:

• Eating fiber. Fruits, vegetables and whole grains pass more easily through the alimentary canal. Fiber gives stool bulk and softens it, which helps prevent constipation and diarrhea. A diet rich in fiber may also help prevent hemorrhoids, diverticular disease and colorectal cancer.
  
  
• Reducing fats and oils. Excessive consumption of foods high in fats, especially saturated fats (foods that contain high levels of saturated fatty acids) and trans fatty acids (unsaturated fatty acids formed when vegetable oils are processed and made more solid) can slow digestion and lead to heartburn, bloating and constipation. A high-fat diet can also worsen conditions such as irritable bowel syndrome, pancreatitis and Crohn's disease as well as increase the risk of colon cancer.
  
  
• Drinking water. People should consume at least eight 8–ounce servings of water throughout the day. Water lubricates food waste so that it passes more easily through the alimentary canal. It also helps soften stool, which may prevent constipation. In addition, water helps dissolve minerals, vitamins and other nutrients, thereby facilitating their absorption by the body’s tissues.
  
  
• Reducing or avoiding alcohol consumption. Health experts recommend that women consume no more than one alcoholic beverage a day and men no more than two. Alcohol can inflame the lining of the stomach and relax the lower esophageal sphincter (the valve that prevents stomach acid from backing up into the esophagus), which can cause heartburn and gastrointestinal bleeding. In addition, alcohol can worsen symptoms of nausea and diarrhea.
  
  
• Eating moderate portions at regular times. Large meals cause abdominal distension and bloating.  Excessive fat, carbohydrate and fluid can cause diarrhea. Skipping meals can lead to excessive hunger, which often leads to overeating and puts a person at risk for weight gain.
  
  
• Chewing food slowly and completely. Fast eating increases the likelihood of swallowing excess air, which can lead to heartburn, belching and gas and bloating.
  
  
• Maintaining a healthy weight. Extra weight increases pressure within the abdomen and stomach, which can lead to bloating, constipation and gastroesophageal reflux disease, conditions that are more common among people who are overweight or obese.
  
  
• Getting regular exercise. Sustained physical activity (aerobic exercise) stimulates functioning of the intestinal muscles, thereby helping push more food waste through the intestines faster.
  
  
• Minimizing stress. Stress can either slow down digestion, which can trigger heartburn, bloating and constipation, or it can speed it up and lead to abdominal pain and diarrhea.
  
  
• Avoiding smoking. In addition to increasing a person’s risk for various types of cancer, cigarette smoking can contribute to heartburn and peptic ulcers. Health experts also believe that smoking can increase the risk of Crohn's disease.
  
  The nicotine in tobacco can lead to excessive stomach acid and not enough sodium bicarbonate, a substance that neutralizes stomach acid. Air swallowed during smoking can produce belching, bloating and gas. Smokeless tobacco (e.g., spit tobacco, chew, snuff, dip) is just as hazardous.

• Consulting a physician before using any medications. The prolonged use of any medication can affect a person’s digestion over time. For instance, narcotics taken for pain relief may result in nausea or constipation. High blood pressure drugs may cause diarrhea or constipation, and some antibiotics may cause nausea or diarrhea. Nonsteroidal anti-inflammatories (e.g., aspirin, ibuprofen, naproxen) can result in stomach pain, diarrhea, ulcers and gastrointestinal bleeding when taken regularly or if the recommended dosage is exceeded.