Irritable bowel syndrome (IBS) is a condition characterised by abdominal pain and erratic bowel habits. Both stress and diet have been associated with the development of irritable bowel syndrome, and it is possible that these two factors interact in sensitive individuals to cause the condition. A number of dietary factors have been shown to lead to symptoms of irritable bowel syndrome in sufferers, with certain carbohydrates being one potential problematic food. These can be poorly absorbed in susceptible individuals, and they then pass to the bowel and this can lead to fermentation by colonic bacteria, with fermentation leading to the production of gasses that can cause bloating and discomfort. A number of carbohydrates have been identified that can be poorly absorbed in certain individuals including a range of monosaccharides (e.g. fructose), disaccharides (e.g. sucrose and lactose), oligosaccharides (e.g. fructo-oligosaccharides and maltotriose) and polyhydric alcohols (e.g. xylitol).
One of the most consistent characteristics of irritable bowel syndrome is the link to anxiety, depression and other negative mood changes, particularly stress. This suggest that hormonal changes to lead to the characteristic symptoms of irritable bowel syndrome. However, the fact that correlations between stress and irritable bowel symptoms are modest suggest that there are other factors that interact with stress to cause the condition. Because stress is associated with decreased bowel transit times, it may be that the presence of the stress hormones is able to prevent the correct digestion and absorption of certain foods, and this effect then has a negative effect on bowel function. A number of foods have been identified in this regard, with certain carbohydrates being likely contributory factors. Overall the aetiology of irritable bowel syndrome in complex, but where possible sufferers should avoid stress and other negative mood changes.
However, it has been suggested that the presence of poorly digested carbohydrates are not enough in isolation to cause the symptoms of irritable bowel syndrome. In this respect, other factors may interact with the changes in the gut caused by the carbohydrate. One such factor might be the presence of stress hormones, which change the motility of the gut and exacerbate the malabsorption of the carbohydrates. For example, in one study researchers applied intravenous corticotropin-releasing factor (a stress hormone) to the small intestine and then estimated the absorption of 40 grams of fructose in a test meal. The corticotropin-releasing factor increases salivary cortisol release and reduced the small intestinal water content following fructose ingestion. There was also a significant increase in the volume of the ascending colon. The authors concluded that corticotropin-releasing factor can constrict the small intestine and increase fructose malabsorption in sensitive individuals susceptible to irritable bowel syndrome.
Eat Well Stay Healthy, Protect Yourself
RdB
