Hello, Thank you for your query. This sound like a diaper rash. * have you changed his diet recently? *how are his stools now? Any change in color? Is it loose? *are you giving him any oral medications? Or given recently? *any change in diapers? *does he cry while passing urine or stools? *do you still breastfeed? I recommend : -b4 nappy diaper cream after every stool. Make sure to wash with clean water and dry area before applying it. Apply liberally near the anus and on affected area. There should be a thin layer of white cream. Do not apply on penis. (place he passes urine) -avoid diapers. At least, change immediately after it is soiled. This warrants frequent checking and maybe waking at nights. -use cotton cloth nappies and wash frequently in warm water and dettol. Rinse off with fresh water finally If you have made any changes to his diet, certain acidic foods, too much lactose, can cause irritation and hence the rash. It should settle in a week or so. If it doesn t reduce, or shows signs of infection (pus or red skin with peeling /oozing), or it spreads or if he cries while passing urine/motion, please take him to a pediatrician. Hope this helps. Please let me if there is anything else I can help you with. Wish you all good health.