The time it takes for dissolvable or absorbable stitches to disappear can vary.
Most types should start to dissolve or fall out within a week or two, although it may be a few weeks before they disappear completely. Some may last for several months.
Ask your doctor about the type of stitches you have been given and how long they should take to dissolve.
If your wound has healed and your stitches are bothering you, you might want to consider making an appointment with a GP or practice nurse, who may be able to remove them, rather than waiting for them to dissolve completely.