Background and Objectives: Zyactinase® is an extract of green kiwifruit, formulated into the consumer healthcare products marketed as Phloe® and Kivia, used to assist in the relief of the symptoms associated with a range of digestive system dysfunction, including constipation and Irritable Bowel Syndrome (IBS). Methods and Study Design: A randomised, double-blind, placebo-controlled clinical trial was undertaken to determine the ef- fects of the kiwifruit extract on bowel movement, stool formation and IBS associated symptoms amongst a sub- ject group of generally healthy individuals experiencing a period of moderate constipation. Fifty-eight partici- pants were randomized to the kiwifruit extract (28) or placebo (30). Selection criterion was decreased number of bowel movements (<3/week), with increased faecal hardness and IBS associated symptoms. The study ran for three weeks, with participants first undergoing a seven-day wash out period, followed by a seven-day dosing pe- riod, and then a seven-day follow up period. Results: There was a significant increase in the defecation frequency (p<0.001), with a significant improvement in faecal score (p<0.01). There was a significant difference in painful defecation and abdominal pain between the two groups (p<0.01). No side effects, including diarrhoea, urgency or abdominal pain, were observed during the trial. Conclusions: The green kiwifruit extract significantly induced normal bowel movements with no adverse effects. The kiwifruit extract relieved constipation and the symptoms of IBS such as bloating, flatulence and abdominal pain.