Manevac Granules 400g A fibre product for the gentle relief of constipation. Manevac granules contain two active ingredients, ispaghula & senna. Both of these are laxatives. Manevac Granules are within the group of medicines known as stimulant laxatives. They are used to treat constipation & they work by encouraging the bowel to contract & move waste products along the bowel. Menevac Granules can be used for: Short-term use for occasional constipation. Bowel regulation in bed-ridden patients & pregnant women. Pain free evacuation in cases of haemorrhoids.