Prolonged use of senna (senokot)

[Marshiekl]

My son is 9, has mild cerebral palsy and has had chronic constipation since he went onto solid food. In March he began a programme of a daily senokot dose to shrink his 'baggy' bowel. This worked well for a while but the last couple of months it's stopped working and I feel his constipation has actually got worse. Could this be due to the prolonged use of the senna? Does anyone have any experience of this? Any advice greatly appreciated.