which antibiotics is safe in infants gastroenteritis?

child aged 4 yrs, came with pain abdomen, loose motions, fever. The child responded with symptomatic treatment. Reports attached. Diagnosis & management.

Aged 2 years purchased 30 days ago said to be mated 65 days back not pregnant now it is having bloody diarrhoea blood in vomitus what could be the cause it was given inj ranitidine inj enrofloxacin inj RL treated for Haemorrhagic Gastro Enteritis

65yrs old female patient comes with loose stools and vomiting since 2days.. urge to water.. Tachycardia-200bpm BP- 110-90mm/HG On ivestigation- Platlet count -initialy at the time of admission- platelet count-86000 after 6hours platlet count is 109000, Blood urea-70mg/dl, RBS-185mg/dl Puffiness over face H/O NIDDM from 2yrs Plz suggest me the diagnose and treatment

14-month-old male presented with a 3 day history of watery diarrhea that has progressively worsened and is now green, mucusy, with lab confirmed blood (small amounts seen in the last pictures). Patient otherwise fine until day 3 when he developed fever 101.5 max. Diarrhea occurs about every 1-2 hours. No abdominal pain/nausea/vomiting. Decreased appetite but drinking fluids (water, mom still breastfeed, and also supplements with goat milk formula due to past suspected cows milk protein intolerance). No changes to diet except mom started to introduce formula milk and states baby has been eating eggs more regularly and used to have an egg intolerance which she thought he had outgrown. Stool cultures and allergy referral pending. Thoughts? Infectious or allergic?

27yr old c/o headache , diarrhoea , chest pain , weakness . o/e pulse - 114/min, BP: 110/50 mmHg . what is the diagnosis and treatment of this case ? And what this ecg suggest?