Constipation is a common problem for adults and paediatric patients and can generate considerable suffering for patients due to both the unpleasant physical symptoms and psychological preoccupations that can arise. Since disaccharide sugar is widely prescribed osmotic laxative in India, we decided to do systematic review to compare the efficacy and safety of lactitol versus lactulose in the management of constipation. All randomised, non-randomised and open trials, with head to head comparison of lactitol versus lactulose were included. After intense literature search we included six clinical trials for comparison. The relevant studies that were included in meta-analysis included 349 adult patients with mean age group of 19 to 85 years and 81 children from age group of 8 months to 16 years. Duration of treatment was 3 days to 4 weeks. In terms of efficacy lactitol was found to be comparable to lactulose in terms of normal consistency of stool and number of bowel movement per week. Better acceptance by the patients was reported with lactitol as compared to lactulose (73.2% versus 26.8%). Lactitol was found to be significantly superior as compared to lactulose in terms of less number of adverse events (31.20 +/- 0.8000% versus 62.10 +/-1.100%, p = 0.0019). Better efficacy was adjudged by the physicians in favour of lactitol as compared to lactulose (61.91% versus 47.83%). In addition compliance with lactitol was found to be better due to superior palatability. Also in paediatric patients the dose of lactitol required was almost half the dose of lactulose (250-400 mg/kg/day versus 500-750 mg/kg/day). Lactitol should be preferred over lactulose in the management of chronic constipation because of its superior efficacy as adjudged by the physician, better palatability, lesser incidence of adverse events, better acceptance and compliance reported by patients.