Hello from justAnswer.
It is generally better to limit the long term use of stimulant laxatives, such as Dulcolax. It would be better to use fiber laxatives or Miralax.
It also would be an option to try medicines that can help calm the irritated nerves and muscle contraction involved in IBS. This is most often done with certain antidepressants, such as imipramine. Newer antidepressants are tolerated with less side effects, although are not as well studied in IBS.
If I can provide any clarification, please let me know.