Hi Vonnie,
I dont know how long you have been taking imatinib but in terms of the side effect profile and you can do this by looking at the product literature that accompanies your medicines, it is not uncommon to experience nausea and headaches and sometimes vomiting as a side effect and this might be especially so if one does not take lots of water with your pill and accompany it with a substantial meal.In addition many CML patients on imatinib experience what I call in polite terms faecal looseness and bloating, so sometimes it pays to be near the bathroom.Looking back on forum these two side effects have often come up for discussion.
I still have these two issues that you mention even after 15 years on the tki; because of another issue of having had radiation implants in my prostate the situation of bowel movements/lower intestinal bloating is exaggerated.My urologist has suggested to use "Normacol "-it comes in sachets and can be added to cereal ideally in the morning and is available from all good pharmacies off prescription.Apparently it is a natural product of fibre based ingredients that normalises any digestive and bowel problems and regularizes bloating.It is available on Amazon if you cannot find it otherwise.
I like David suggest to you that the fish might be a coincidence rather than a cause.
With best wishes
John