Thanks Charm for your suggestions. It doesn't happen very often now so hopefully as the mucositis gets better, it will go away. The retching seems to happen when there is a big ball of mucous lurking somewhere and he tries to drink something.
Anne

Anne - CG to Gordon (59), non-smoker/non-drinker. SCC, BOT, HPV 16+, stage 3. Jan./10 - radical neck dissection to remove 48 lymph nodes, 1 node pos. Apr. 23/10 - finished 35 rad. and 3 cisplatin. Jul. 22/10 - PET scan clear.