The relationship between FODMAP intake and acute gastrointestinal symptoms in adults with Irritable Bowel Syndrome (IBS)

Abstract

Background: Diet is known to play a major role in irritable bowel syndrome (IBS) with many people identifying certain foods as a trigger for symptoms. Recently, reducing fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) has been shown to help alleviate symptoms in IBS patients. The mechanisms through which FODMAPs trigger symptoms have been well established, yet there are limited studies investigating the relationship between FODMAP content in the diet and IBS symptoms. Although, patients have reported symptom onset in the following few hours after a meal, there has been limited research surrounding acute symptom onset and its relationship with FODMAP intake.

Objective: The aims of this study are to investigate the relationship between dietary FODMAP intake and acute gastrointestinal symptoms in IBS adults and the effect of individual FODMAPs on these acute gastrointestinal symptoms.

Design: Data were collected from 103 participants from two IBS cohorts; the Christchurch IBS COhort to investigate Mechanisms For Gut Relief and Improved Transit (COMFORT) study and the Food And Symptom Times (FAST) validation study. Relevant data collected included demographic forms, diagnostic questionnaires and food and symptom data. Participants completed a three-day food and symptom diary over three non-consecutive days. Symptoms assessed included abdominal pain, abdominal bloating, abdominal swelling, abdominal distension and bowel motions which were recorded on a 24-hour scale stating the time, duration and severity. All food items and beverages from the food diaries were entered in a FODMAP analysis software to analyze the FODMAP content of each meal. Symptom data were recorded into an excel sheet. ANOVA tests and receiver operating characteristic (ROC) curves were used to investigate the relationship between FODMAP intake and acute gastrointestinal symptoms and the effects of individual FODMAPs on these symptoms.

Results: The presence of abdominal pain and bowel motions following a meal were associated with a significantly higher intake compared to those not experiencing symptoms for both FODMAPs (3.98g v 3.24g and 4.27g v 3.12g, p<0.05), and for fructans (0.77g v 0.48g and 0.76g v 0.47g, p<0.05). Overall there were no significant correlations between increasing FODMAP intake and the proportion of people experiencing abdominal symptoms. A significant correlation was found between increasing FODMAP intake and the proportion of people with acute bowel motions following a meal. Oligosaccharides (GOS and fructans) had significant correlations between increasing intake and the percentage of patients experiencing abdominal pain, abdominal, fullness and bowel motions (p<0.05). There was no significant difference between average FODMAP intake and the severity of acute symptoms reported. A significantly higher intake of lactose was associated with lower severity of fullness and swelling compared to those reporting higher severity and a higher excess fructose intake was associated with a higher severity of abdominal swelling.

Conclusion: These findings support the role of FODMAPS in acute symptom onset however, the amount and type of FODMAPs triggering symptoms varies between individuals for most FODMAPs. This study highlights the importance of individualized dietary advice given by a dietitian to help manage IBS symptoms and determine individual thresholds.