Sugar malabsorption in functional abdominal bloating: a pilot study on the long-term effect of dietary treatment

Clin Nutr. 2006 Oct;25(5):824-31. doi: 10.1016/j.clnu.2005.11.010. Epub 2006 Jan 10.


Background: Functional abdominal bloating is a functional bowel disorder dominated by a feeling of abdominal fullness without sufficient criteria for another functional gastrointestinal disorder. Gas-related complaints (i.e., passage of flatus), which are present in a subgroup of these patients, might be associated with carbohydrate malabsorption.

Aim: To evaluate the presence of lactose and/or fructose plus sorbitol malabsorption, and the long-term efficacy of malabsorbed sugar-free diets, in patients with Rome II criteria of functional abdominal bloating and gas-related symptoms.

Methods: Thirty-six consecutive patients (age, 51+/-3.1 years; sex, 12 M, 24 W) with Rome II criteria of functional abdominal bloating and gas-related symptoms were included in a pilot study. In all cases, the presence of malabsorption of both lactose (20 g) and fructose plus sorbitol (20+3.5 g) was assessed by means of hydrogen breath test. Patients with sugar malabsorption were put on a malabsorbed sugar-free diet. Follow-up visits were scheduled at both 1 and 12 months after starting the diet. Global rating scales of change as compared to the beginning of the study were used to assess symptom changes.

Results: Twenty-six of 36 patients (72.2%) presented sugar malabsorption (six lactose, 12 fructose plus sorbitol, and eight both). Seventeen of the 26 (65%) patients with malabsorption had symptoms of sugar intolerance during the 3-h breath testing period. All 26 were put on malabsorbed sugar-free diets. Eighty-one per cent of patients referred clinical improvement at 1-month visit, which was maintained at 12 months in 67% of them (complete improvement in 50% and partial improvement in 16.7%).

Conclusions: Sugar malabsorption and intolerance seem to be frequent in patients with functional abdominal bloating and gas-related complaints. A malabsorbed sugar-free diet might be a long-term effective therapy in a high percentage of patients. Further controlled clinical trials are warranted.

MeSH terms

  • Breath Tests
  • Colonic Diseases, Functional / diet therapy*
  • Colonic Diseases, Functional / etiology
  • Colonic Diseases, Functional / metabolism
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / metabolism*
  • Female
  • Flatulence / diet therapy*
  • Flatulence / etiology
  • Flatulence / metabolism
  • Fructose / administration & dosage
  • Fructose / metabolism
  • Humans
  • Intestinal Absorption
  • Lactose / administration & dosage
  • Lactose / metabolism
  • Lactose Intolerance / diet therapy
  • Lactose Intolerance / etiology
  • Lactose Intolerance / metabolism
  • Malabsorption Syndromes / diet therapy*
  • Male
  • Middle Aged
  • Pilot Projects
  • Sorbitol / administration & dosage
  • Sorbitol / metabolism
  • Treatment Outcome


  • Dietary Carbohydrates
  • Fructose
  • Sorbitol
  • Lactose