Methods for treating gastrointestinal conditions, conditions associated with sympathetic and/or parasympathetic activity in the gastrointestinal organs, and conditions associated with central sympathetic and/or parasympathetic activity in a patient with therapeutic gastrointestinal neuromodulation and associated systems and methods are disclosed herein. One aspect of the present technology is directed to methods that at least partially inhibit sympathetic neural activity in nerves proximate a gastrointestinal artery of a gastrointestinal organ of a patient. Sympathetic drive in the patient can thereby be reduced in a manner that treats the patient for the gastrointestinal condition. Gastrointestinal sympathetic nerve activity can be modulated along afferent and/or efferent pathways. The modulation can be achieved, for example, using an intravascularly positioned catheter carrying a therapeutic assembly, e.g., a therapeutic assembly configured to use electrically-induced, thermally-induced, and/or chemically-induced approaches to modulate the gastrointestinal nerve.