on diet image by anna karwowska from Fotolia.com

With the obesity epidemic on the rise, many people turn to extreme diets to lose weight. Liquid diets are a popular rapid weight loss method and also the recommended diet after bariatric or lapband surgery. In addition, liquid diets are sometimes used to treat conditions such as diverticulitis and irritable bowel syndrome (IBS) to help reduce bowel obstruction and increase elimination. Although liquid diets may lead to some weight loss, and alleviation of symptoms of IBS, they are often associated with intestinal problems.

Types of Liquid Diets

Liquid diets come in many forms including high fiber, clear and lactose intolerant types and each may have some side effects associated with their use. Clear liquid diets are usually given to patients following gastric bypass surgery, and are also used for cleansing purposes when detoxifying the liver, colon or bowel. They most often consist of water, pure juice and broth. High fiber liquid diets follow the clear diet after bariatric surgery, and are also used for those suffering from symptoms of diverticulitis or IBS to increase bowel function. Liquid diets for those who are lactose intolerant may use soy as a base product and are a substitute for high fiber diet drinks. Some liquid diets are available over the counter, and others only by prescription.

Stomach Discomfort

Ingesting any sort of liquid diet may lead to initial stomach discomfort. High fiber liquid diets lead to an increased need to eliminate, causing the stomach muscles to contract more frequently and produce cramps. This is also likely with clear and soy liquid diets because of the increased overall fiber content and absorption rate. In addition, liquid diets may lead to feelings of extreme hunger as the stomach empties and readjusts to a lack of solid food, causing stomach grumbling and upset. Try eliminating foods slowly before beginning a liquid diet to avoid the shock to your stomach caused by extreme dieting.


Because liquid diets are composed of soluble fiber, or fiber that dissolves in water, their usage is more likely to result in abdominal bloat. According to the National Digestive Diseases Information Clearinghouse, soluble fiber in fruit juices used for liquid diets is not digested until it reaches the large intestine, leading to excess gas accumulation and bloating. Try drinking more vegetable juices to avoid the bloat associated with liquid diets.


Liquid diets may increase the amount of air you ingest due to the swallowing action involved in drinking. This can lead to a buildup of air and gas in the intestine that can cause discomfort and lead to belching. To avoid excess air accumulation that leads to belching, sip liquids slowly or through a straw when on a liquid diet.

Reintroducing Solid Foods

Adding solid foods after having been on a liquid diet can lead to digestive problems such as constipation, cramps and weight gain. The Mayo Clinic recommends introducing foods very slowly in order to digest properly. In addition, drink liquids separate from your meal, and eat several small meals per day. Avoid symptoms such as nausea and vomiting by avoiding foods high in sugar and fat that are more difficult for the digestive system to process following a liquid diet.