Hello and thank you for posting.

I am sorry Dad is having problems with constipation, but I do not know whether there are any issues with his oesophageal cancer diagnosis. What I can say is it is not unusual for people to have changes in bowel habits when there are many life changes like surgeries, treatments, diet changes, and everyday habits are different. 

The sachets that Dad has been prescribed are probably other laxatives to help things move. It is not unusual for people to need a couple of different types of laxatives, like a stool softener and a stimulant to start the bowel back up again.

Diet problems caused by cancer, its treatments, and side effects are common, but if you are concerned about Dad's cancer then do try and talk to his doctor or specialist nurse so you feel up to date. If Dad can let them know that he is happy for his health information to be shared, then you will be able to talk to someone. 

Take care and if you want to call to talk things through you may find it helpful to speak with one of the nurses on our helpline.  The number to call is Freephone 0808 800 4040, and the lines are open from 9am till 5 pm Monday to Friday.

Sarah.