I don't think it sounds like a hiatel hernia, but do think it sounds like an intestinal hernia. I'd certainly have it checked out asap. Areas around surgical incisions are weak spots, and can lead to intestinal blockages, which are very dangerous, something I can attest to. Do check this out. Keep us informed.
It doesn't seem to present that way. According to the mayo clinic -
"A hiatal hernia occurs when part of your stomach pushes upward through your diaphragm. Your diaphragm normally has a small opening (hiatus) that allows your food tube (esophagus) to pass through on its way to connect to your stomach. The stomach can push up through this opening and cause a hiatal hernia.
In most cases, a small hiatal hernia doesn't cause problems, and you may never know you have a hiatal hernia unless your doctor discovers it when checking for another condition. But a large hiatal hernia can allow food and acid to back up into your esophagus, leading to heartburn and chest pain. Self-care measures or medications can usually relieve these symptoms, although a very large hiatal hernia sometimes requires surgery.
[SYMPTOMS]
Small hiatal hernias
Most small hiatal hernias cause no signs or symptoms.
Large hiatal hernias
Larger hiatal hernias can cause signs and symptoms such as:
Heartburn
Belching
Chest pain
Nausea
When to see a doctor
Make an appointment with your doctor if you have any persistent signs or symptoms that worry you. "