Bowel movements are individual, so it is important to pay attention to your normal schedule. Some people have bowel movements more than once a day, whereas others regularly have them three times in a week. If you begin to have fewer bowel movements than what is normal for you, or they are more difficult to pass, you might be constipated. Grapefruit juice is one food that might prevent and improve your constipation, although whole grapefruits might work better.
Fiber for Constipation
Fiber is important to promote regular bowel movements and to prevent constipation, as well as to treat constipation if you already have it. Fiber adds bulk to stool, helping it move through the digestive system. Grapefruits contain anywhere from 1.5 to 2.3 grams of fiber per 154-gram serving. Oranges actually contain more fiber, with 2.3 to 3.4 grams per serving. You will experience more constipation relief from eating a whole grapefruit with the white segment membranes than from juice that does not contain those parts of the grapefruit. Eating the membranes gives you double the fiber from a grapefruit than if you skip them and only eat the flesh between or drink the juice.
Laxative Quality in Grapefruit
Even without the pith, grapefruit seems to have a laxative quality that might improve your constipation. A 2008 article in the journal “PLoS ONE” found that naringenin, a flavonoid anti-oxidant found in citrus fruits, acted like a laxative in rats that were given loperamide to cause constipation; however, research is needed on humans to determine the extent of this potential benefit.
Liquids for Constipation
To ward off constipation and get the most from fiber, you should take in at least eight glasses of liquid per day. That liquid can include juice, explains a December 2010 article in the journal “American Family Physician.” Liquids help soften your stool so they move more easily through your body.
According to Harvard Medical School, grapefruit juice interferes with certain medications used to treat high blood pressure, high cholesterol and psychiatric disorders. If you take any medication, talk to your doctor before using grapefruit juice for constipation.