A wealth of controlled studies have found fish oil to be one of the most versatile, useful supplements for improving a person's overall state of health and well being. Unfortunately, many consumers stop taking fish oil supplements because of unpleasant gastrointestinal side effects like reflux and diarrhea. The U.S. National Institutes of Health offer several guidelines for enhancing absorption of fish oil and decreasing the incidence of malabsorption-related side effects.
Select a high-quality fish oil brand that offers enteric coated capsules. These supplements have a thick coating that protects them from stomach acids, so they pass into the colon without breaking apart. Enteric coated capsules are absorbed entirely by the large and small intestines, so they are less likely to cause vomiting or reflux.
Take the lowest possible dose of fish oil until your body adjusts to the supplement. Your body should "learn" to efficiently absorb fish oil within a few days or weeks. After you stop experiencing reflux or stomach upset, gradually increase your dose to the level recommended by your doctor or nutritionist.
Take fish oil capsules during or directly after a large meal. The National Institutes of Health state that this can enhance absorption of omega-3 fats while preventing gastrointestinal side effects and discomfort.
Do not take fish oil with omega-6 fatty acid supplements. According to the National Institutes of Health, omega-3 and omega-6 fatty acids compete within the body. To maximize your body's absorption of fish oil, avoid taking it alongside evening primrose oil, pumpkin oil, safflower oil, corn oil or sesame oil.
Consider taking a digestive enzyme supplement containing lipase. This natural enzyme breaks fats into small, easy-to-absorb molecules that pass readily into the bloodstream. The University of Maryland notes that most people do not need lipase supplements; however, lipase supplements may help to increase the absorption of omega-3 fats in fish oil.