Isnt this related to the botox a lot of people agree who have taken

the injections in the neck and shoulder area certainly can cause weakness and other symptoms locally in the area including difficulty swallowing but I am not aware of abdominal issues following Botox

Most of the complications from higher quantities of Botox occur at the local and regional sites of injection.   Most people that feel they have had too much in a certain area around the neck and shoulders report the "bobble head" phenomenon, where they feel like it is harder to support their head and neck.  Systemic effects of colitis would be a bit odd; however, I agree with your plan for a through evaluation.  The pain in the neck and skull can come from increased injection sites and volume of injection, and is common, as is its abatement within a short period of one week.