Hi Dear, Welcome to HCM. Understanding your concern. As you describe in your query that you have discoloration of lips after removal of stitches .Well this usually happens after healing process and the condition is known as post inflammatory hyper pigmentation .In this condition melanin pigment get accumulated after inflammatory response. I would suggest you to -: -Avoid sun exposure to prevent further hyper pigmentation ,apply broad spectrum sunscreen. -Apply vitamin E oil to the area of stitches which will promotes healthy skin formation. -Also apply azelaic acid cream once daily. If condition persists for more then a week then you should consult dermatologist .Doctor can prescribe you topical steroid cream or topical antibiotic cream. hope your concern has been resolved. Get well Soon. Best Wishes, Dr. Harry Maheshwari