Irritable Bowel Syndrome (IBS)

Summary - 

IBS (irritable bowel syndrome) affects the large intestine and is characterized by chronic abdominal pain and abnormal or altered bowel habits. It is sometimes referred to as colitis or spastic colon. Although symptoms vary depending on the person, the most common symptoms include abdominal pain and cramps, bloating, constipation, diarrhea, and gassiness. There are several “triggers” for IBS patients that vary considerably. While the cause of IBS is unknown, there are theories suggesting an exaggerated response to stimuli (the triggers) creating an intolerance or hypersensitivity among those affected with IBS. There are different forms of IBS depending on symptoms:

  • IBS-D (diarrhea)
  • IBS-C (constipation)
  • IBS-A (alternating diarrhea and constipation)
  • IBS-M (mixed symptoms)
  • IBS-U (unclassified)

Diagnosis - 

The Rome diagnostic criteria is a common tool to diagnose functional GI disorders (FGID). Please see their latest diagnostic criteria for IBS at

Treatment - 

A Registered Dietitian helps a patient with IBS to create an individualized plan to diet and lifestyle that will help manage GI symptoms, prevent malnutrition, and help the GI tract to function properly again. With IBS, there are certain triggers that affect people differently. For instance, although stress is a common trigger among IBS patients, it is not a trigger for all. Other common triggers include eating large meals, high fat foods, or other foods (see list below). Food and dietary habits are key to managing IBS symptoms.

Common recommendations include:*

  1. Normalize eating patterns, eat at a relaxed pace at consistent times, with small frequent meals, and ensure adequacy of nutrients.
  2. Adjust diet for food allergies and intolerances; common problem foods include wheat, yeast, and eggs.
  3. Reduced lactose (if lactose intolerant or experiencing symptoms upon the ingestion of certain dairy).
  4. Low-FODMAP diet (avoid foods high in fructose, sorbitol, xylitol and mannitol, and gas producing foods).
  5. Use of pre- and probiotics.
  6. Progress slowly to a diet adequate in fiber (25-35 g/day).
  7. Ensure adequate fluid intake of 2-3 quarts of water daily.
  8. Foods to avoid: alcohol, black pepper, caffeine, chili powder, cocoa/chocolate, coffee, colas, garlic, red pepper, spicy foods, and sugars.
  9. Avoid high-fat intake.
  10. Supplement with B-complex vitamins, calcium, vitamin D, and riboflavin (if lactose is not tolerated).
  11. Supplement with 1 tbsp daily of bulking agent, such a Metamucil, which may be helpful meeting fiber needs; avoid bran supplements as it may be irritating.

More elaborate explanation of some recommendations:

  • Eat small, nutrient dense, meals at regular and consistent times. Large meals may exacerbate symptoms, so eating small meals (perhaps more frequently throughout the day) may help. Having a routine will help regulate bowels, hormones, and metabolism. All meals should be nutrient dense to enhance wellness and promote proper nutrition for the body, especially for a patient with IBS-D (diarrhea – where the risk of malnutrition is higher). It is ideal to chew foods thoroughly and slowly to aid digestion and prevent overeating (as large meals may cause problems).
  • Eat a high fiber diet. Fiber is essential for good health and also helps to regulate bowels and prevent constipation. Please contact me when upping your fiber intake, as the process should occur slowly to prevent IBS complications from getting worse. Note: whenever fiber is increased in the diet, water should also be increased as well to help your body adjust. On that note, regardless of fiber intake, water is also essential for good health for many different reasons, one reason being preventing constipation (a common symptom for IBS).
  • Avoid gas-producing foods. Certain foods are prone to cause gas (but remember everyone is different!): cruciferous vegetables like broccoli, Brussels sprouts, cabbage, cauliflower, and beans, peas, cucumber, corn, leeks, and onions. It is wise to keep track of IBS symptoms along with dietary intake in order to identify which foods give you complications. A food journal comes in handy.
  • Often times food intolerance may cause IBS symptoms. Although IBS does not directly damage the intestinal tract, the complications of IBS and the resulting malnutrition can indirectly affect gut health. In addition, there are certain factors that might cause IBS in the first place, such as infections or antibiotic use, which impact gut health directly. Repeated exposure to trigger foods can possibly damage the gut lining even further (a change gut permeability, or also known as leaky gut). It is recommended to follow a FODMAP diet to eliminate common triggers, help identify the foods that cause problems, as well as give the bowel some rest and promote healing. Main idea: you’ll need to manage your personal food intolerances.
  • Avoid other substances that cause symptoms. The foods listed here are common triggers for IBS, but triggers vary wildly. Alcoholic drinks, caffeine, sugar alcohol, and sometimes the sugar in fruit may effect IBS patients. The main idea is to identify what causes symptoms for YOU so you can avoid them. If you are interested in following a low FODMAP diet, feel free to contact me for guidance.
    • See information below on a low FODMAP diet!
  • Practice stress management. Stress and anxiety effect bowel health tremendously, and stress is a common trigger for IBS patients. It is vital to practice stress management techniques.
  • Certain medications and supplements might affect the GI tract. See a doctor or dietitian if you are taking medications, as certain ones can make symptoms worse (such as antacids) or affect bowel movements (like some herbal supplements). 
  • Pre- and probiotics. Depending on your health and personal IBS symptoms, probiotics might be recommended to promote healthy gut bacteria.


(Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) – certain carbohydrates which may be poorly absorbed in the small intestine and pass through to the large intestine largely undigested. As a result, fermentation in the large intestine occurs, which may cause increased gas, abdominal distention, bloating, cramping, and diarrhea. Here is a common list of FODMAPs:

  • Fructans: garlic, inulin, onion, wheat
  • Fructose: fruit, high fructose corn syrup, honey
  • Galactans: legumes, like beans, lentils, and soybeans
  • Lactose: dairy
  • Polyols: apricots, avocados, cherries, peaches, and plums and sugar alcohols like mannitol, sorbitol, and xylitol
  • Please see this link for a complete list

o   A low FODMAP diet might be difficult to follow because there are so many different foods included in this list. It is best to work with a healthcare professional who specializes in a low FODMAP diet in order to make sure you are meeting your nutritional needs. It is recommended to follow the diet for 6-8 weeks in order to see if the diet is effectively easing symptoms, and regular follow ups are essential during the process to keep you on track and make sure you are meeting your needs. After ~6 weeks, you can slowly reintroduce foods in order to determine if certain foods trigger your symptoms. 

Bottom line - 

IBS is a multifaceted condition that can be exacerbated by various factors including stress and poor diet. There is no one-dietary strategy for IBS as one solution might work for one client but not another. It is best to work with a Dietitian in order to identify trigger foods and follow a personalized plan created just for you.

Resources - 

Visit  Kate Scarlata, RDN/FODMAP + IBS exper t for more resources

Visit Kate Scarlata, RDN/FODMAP + IBS expert for more resources