Hi Sarah:
Abdominal epilepsy was the first thing that crossed my mind, even before you brought it up at the end of your question.
Abdominal epilepsy is an exceptionally rare syndrome of epilepsy that's more likely to occur in children. Even rare, I have seen 2 cases in my practice of 30 years.
With abdominal epilepsy, seizure activity causes abdominal symptoms. For example, it may cause pain and nausea and
vomiting. Anticonvulsant medications can improve the symptoms.
With abdominal epilepsy, it's thought that seizures occur that primarily affect the digestive system. Gastrointestinal symptoms are the result. Those symptoms include:
abdominal pain, usually sharp or cramping and lasting seconds to minutes, nausea and/or vomiting,
fatigue,
lethargy, or sleep following seizures, altered level of consciousness, such as confusion or unresponsiveness.
Abdominal epilepsy is so uncommon that some experts question whether it exists. Abdominal pain is common in people with epilepsy as well as without.
I recommend a neurological evaluation, EEG, to clear that diagnosis.