Its been 9days that i deliver a 5month child due to the some abnormality...and now is it fine to do anal sex

Hard to say: You provide no specific information on the conditions of birth.You didn't deliver it a woman did. The condition of her vaginal structures cannot be assessed on line, if torn or eroded, anal sex could injure them to the point they tear and she ends up pooping through her vagina. Best ask someone who is involved with her care that knows her status.