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Spotting/altered discharge during or after intercourse could be suggestive of causes like vaginal infections, PID, pregnancy, adenomyosis, endometriosis, cervical infections, cervical erosion, cervical dysplasia, etc. The exact cause can only be made out after careful evaluation and investigation. Visit your doctor/gynecologist for further examination and investigations to look for the underlying cause. Treatment as appropriate (based on the examination findings and investigation results) would be started to help you. Avoid further sexual intercourse until cleared by your doctor/gynecologist. If infective cause is detected, get your partner also treated simultaneously to prevent chances of re-infection. Drink plenty of water. Take adequate rest. Avoid vaginal douching, use of harsh soap or perfumes in the area. Use loose cotton undergarments and avoid tight fitting clothes.
Take care.