It is not uncommon for antibiotics to be used when treating inflammation alone. I think there perhaps there is an assumption that because inflammation is present the bowel wall has been breached and the antibiotic is used in a prophylactic sense in case infection is present.
I don't know about Cipro but I have read studies that suggest Flagyl (Metronidazole) has both antibiotic and anti inflammatory properties.
Dusty. xxx