Co-occurrence of IBS, functional dyspepsia linked to increased gastrointestinal symptoms
Among patients with irritable bowel syndrome (IBS), those with functional dyspepsia (FD) appear to have increased gastrointestinal (GI) symptoms both before and after a liquid meal with lactulose, a study has shown.
The prospective study included 205 patients with IBS (Rome III criteria), 94 of whom also had FD (IBS-FD), and 83 healthy controls. All participants underwent a breath hydrogen test after a 400-mL liquid meal with 25 g lactulose.
GI symptom severity was evaluated using a graded scale, and digestive comfort was assessed prior to the meal and every 15 minutes until 240 minutes after the meal. GI symptom scores over time were calculated and compared between groups using linear mixed models controlled for anxiety, depression and somatization.
Over time, average GI symptom levels varied among all groups (p<0.0001). Compared with patients with only IBS, those with IBS-FD had higher levels of bloating (p=0.004) and abdominal pain (p=0.005), and reduced levels of digestive comfort (p<0.01).
Increase in abdominal pain from baseline differed between the IBS-FD and IBS groups (p=0.013). Anxiety levels were related to levels of all GI symptoms (p<0.025 for all), with the exception of abdominal pain, and to exhaled hydrogen level (p=0.0042). Meanwhile, abdominal pain was associated with somatization severity (p<0.0001).
The findings demonstrate the independent effects of comorbid FD, anxiety and somatization levels on postprandial GI symptom reporting in IBS, researchers said. Furthermore, lactulose nutrient-challenge testing proves to be useful for characterizing IBS patient symptomatology and its underlying mechanisms.
Researchers recommended evaluating and controlling for FD status in trials exploring new treatments for IBS.