Adhesions

They will have told you everything that they know - doctors don't keep things from patients these days. As you say, he would probably have been told if they are looking for tumours. If they say adhesions, then adhesions are what they expect to find.
MRI scans are not just done for suspected tumours, they show details of soft tissue well, so they will show a surgeon the area on which he could be operating. I don't know whether adhesions will be clearer on an MRI than on a CT scan, but it is always a good thing to get a different kind of picture.
If you are worried about what they may also find in further investigations, then you need to contact the unit directly and ask them your questions. They are used to patients and relatives talking to them about their diagnosis and treatment.