<s>[INST] Hi -my son is 5 wks old (approx 4.5kg) and has a marginally enlarged kidney which is making me worry about giving him gripe water for his tummy problems. I gave gripe water last night and it worked wonders so I would love to keep giving it rather than have him suffer in pain and cry for 3hrs in a row at night.  The bottle warns about giving it to anyone with impaired kidney function - does this include my sons problem or do they mean some more sever kidney problems instead? Mia [/INST] Hello Mia and welcome to Chat Doctor. As a Urologist, i can understand your anxiety. The mild enlargement of kidney, isnt anything to worry about. This is considered as normal, up to a difference of 2 CMS, between the two. Kidney function is tested by doing a blood creatinine test. The enlargement seen on an ultrasound scan, is of no consequence. The scan and creatinine, need to be re-checked after a month. If you've any doubts, send me all the reports, as a direct question. Chat Doctor.  Manga. </s>