Thank you for your query on Healthcare Magic.
Repeated chest infections, poor weight gain, thin built, protruded stomach all these are suggestive of an underlying chronic problems and evaluation should be done to rule out these problems :
1.Congenital heart problem
2. Underlying immunodeficiency
5. Endocrinological problems
Child needs complete physical examination, systemic examination including interpretation of his weight, height, and full investigational work up to rule out any underlying problem.
Therefore I advise you to consult your Pediatrician
for full evaluation.
For loose motions , you can give sips of oral rehydration solutions like Pedialyte
to maintain hydration.
Hope I have answered your query.