Background Conventional medical treatment for constipation typically consists of dietary modification, increased fluid intake and exercise frequency, but many people do not respond to these interventions. Osteopathic treatment is claimed to restore normal function to the digestive system and related somatic structures and may provide an effective treatment for constipation. Objective To examine the effect of osteopathic manipulative treatment for people with chronic constipation over a four week period. Methods Six participants (mean age 48.5 ± 14.1 years) with chronic constipation were treated utilising a semi-standardised osteopathic treatment. Each participant was examined and treated six times over four weeks. Treatment outcomes were measured pre-treatment, during and one week following the treatment period using validated outcome measures specific to bowel function. Results Following treatment there was a significant improvement in the severity of their constipation ( p < 0.01), overall symptom improvement ( p < 0.01), improved colonic transit times ( p < 0.01) and overall quality of life ( p < 0.01). Conclusion Participants reported an improvement in the overall severity of constipation, symptoms and quality of life. Further investigation of osteopathic treatment of constipation is recommended using larger sample sizes and a randomized controlled design.