On Antibiotics For A Colon Infection. Experiencing Severe Diarrhoea. Looking For Suggestion
Grainy stool generally is undigested food because of fast transit due to diarrhea.
No improvement in two weeks / still loose and frequent stools / antibiotics > suggests the need to SEE THE DOCTOR AGAIN.
The normal bacterial flora of bowel might have been lost from antibiotic and could perpetuate it / the original agent was not sensitive to the antibiotic / there could be a different infection / at times amoeba / rarely superinfection with other bacteria - clostridia / these are all some possibilities.
Under these circumstances, your original doctor will be the best to deal with it. More investigations may be needed in view of her age and past history of IBS.
Wishing your mother a speedy recovery. Do let me know if you have more concerns.
Good luck