The abdominal distension or bloating can be due to multiple causes:

• Liver dissorders
• Constipation
• Gastroesophageal reflux
• Colitis or irritable bowel syndrome
• Pancreas damage
• Intolerance to lactose, gluten or other food.
• Intestinal obstruction
• Air degution (stress asociated)
• Bacterial proliferation in the intestines

The medicine for diabetes acarbose, like any medicine that contains lactulose or sorbitol, can cause distension. It can also be caused by ascites, which is the accumulation of fluid in the peritoneum, in turn caused by liver disorders: hepatitis, fatty liver, alcoholism or congestive heart failure.