I am not sure how young your wife is. Since different conditions
cause different symptoms depending on the age and sex , it is
hard to guess. However, based on the information you have
provided, I think the doctor may be treating her for H.pylori
infection that can affect the stomach and cause ulcer involving
the duodenum.(Beginning portion of the small intestine
Usually, three antibiotics along with a PPI (Such as Omeprazole
are used for atleast ten days to cure this bug. If this is not
treated properly, the infection will come back.
The other possibility is some kind of gastroenteritis
caused by eating some contaminated food or drink.
I think you should discuss this with her doctor and have her get
some blood tests and also stool examination.
There is a stool antigen test for H.pylori , if positive will indicate
active infection that needs treatment.
Lower abdominal pain
, fever, diarrhea, can indicate Diverticulitis
inflammation of one of the pockets or pouches on the large bowel.
This is more common after the age of 55-60.
Hope this information helps your wife.
Wish her well.