Mineral oil has long been a popular home remedy for constipation. It coats the intestinal surface so water can't be absorbed. The water then swells and softens stool so that it can be pushed from the body. The lubrication also eases pain from bowel movements. Although this is a traditional remedy that has been used relatively safely, there may be some side effects.
Just as mineral oil limits the absorption of water through the intestines, it can also interfere with the absorption of other medicines and vitamins. Wait at least two hours after taking mineral oil before taking other medications.
Stool softeners can interfere with the action of mineral oil and cause the mineral oil to be absorbed into the body. Again, take mineral oil and stool softeners at least two hours apart.
The anti-absorption properties of mineral oil may interfere with the absorption of vitamins and nutrients from food. Vitamins A, D, E and K, in particular, are essential nutrients that mineral oil is known to block. This can be particularly dangerous for fetal development so mineral oil should not be used during pregnancy. Space mineral oil and meals at least two hours apart. If you must use mineral oil, do not use for longer than a week, according to the American Cancer Society.
Mineral oil may cause diarrhea, leading to dehydration and nutrient loss. Drink 2 to 3 qt. of fluid a day, including those with electrolyte replacements such as chicken broth or sports drinks. Potassium and salt loss from diarrhea can cause potentially harmful conditions, including abnormal heart rhythms and muscle cramps. If the diarrhea is severe, drink a sports drink made specifically for electrolyte replacement, available at most grocery or drug stores.
Mineral oil can cause allergies in some people. Symptoms include rash, hives, breathing difficulties, chest tightness and swelling of the mouth, face, lips or tongue. Contact a doctor immediately if these symptoms occur.
Some people develop a dependence on mineral oil or other laxatives, and their bodies forget how to produce bowel movements naturally. Call a physician if you fail to have a bowel movement within six to eight hours of taking mineral oil, or if you have symptoms such as rectal bleeding, vomiting, abdominal pain, nausea or blocked intestine.
Mineral oil can also affect blood thinners. Because it restricts the absorption of vitamin K, a critical factor in blood clotting, it can cause the blood to thin abnormally, increasing the risk of excessive bleeding. This can also be a danger for pregnant women. Check with your physician before using mineral oil if you are taking blood thinners or are pregnant.