Different laxatives for treating constipation

[Minnu]

Hi, my uncle is 75 years old. He is very active and comparatively healthy than his friends of similar age. He goes for walk regularly and does lot of exercise. His lifestyle is also in compliance to a healthy system. But very recently he is facing some health issues. He is suffering from irregular bowel movements and constipation. Is there any laxative for treating constipation? What are all the different types of laxatives available?

[Nimmy]

@Minnu Bulk-forming laxatives (such as ispaghula husk), which work by increasing faecal mass, but they may take several days to become fully effective. They are of most use in those patients that pass small stools and have a diet lacking in fibre (but they should not replace dietary lifestyle measures)
■ Faecal softeners (such as docusate, which is stimulating but which also has softening properties). These can be useful where passing stools may be uncomfortable e.g. with haemorrhoids
■ Osmotic laxatives (such as lactulose) work by drawing fluid into the bowel and retaining the existing fluid. They may take several days to become fully effective and it is essential that fluid intake is maintained during their use.