Thanks for writing in to Healthcare Magic!
Three important diseases of gut can cause a pain abdomen like that
Ischemia- decreased blood supply
inflammatory bowel disease
Ischemia is dangerous and typically occurs in elderly persons and also in diabetics and hypertensives. this is a serious possibility and hence you should repeat an ultrasound
abdomen in two days to see the condition.
To treat the infection you current treatment id okay; continue it for 5days at least.
If you have any further query please let me know I would try to answer it for you.
Wish you a great health!