Hi
You have not mentioned about the frequency of stools.
Breast fed babies can pass pasty stools. And some kids on formula milk may pass green stools too.
Pus cells in stools is not normal. But
E.Coli is a normal bacteria seen in intestines.
Since your baby is on medications already, please complete the entire course as prescribed.
Since weight gain is okay, you need not worry much.
Regarding the feeds- try to put him on exclusive breast feeds till 6 months of age. Formula milk is known to produce these gas problems more. And please stop using bottle. Its going to cause more harm like frequent
diarrhea,
yeast infections in the mouth and ear infections too. Bottle feeding will in turn reduce the breast milk output. So till 6 months of age, EXCLUSIVE BREAST MILK is the best for your baby.
For the gas problem- Try to burp him after each feeds by giving gentle pats on his back between shoulder blades after each feeds till he belches the air out.
And as a part of routine
massage, give these strokes to his tummy- circular strokes around the belly button, strokes in the form of inverted L and inverted U.
You can also apply a warm towel on his tummy when he cries excessively.
With these, the gas problem will definitely come down.
Medications like colimex can be given for few days.
When you give gripe water, be sure its clean and devoid of alcohol.
Medications like colicaid- that contain fennel seed oil and
simethicone are safe to be given for a longer time.
Hope I have answered your query.
Wish your baby boy good health.
Happy parenting!