Dear Concerned., Thanks for writing to us. You have been prescribed Lymecycline as it belongs to a group of Antibiotics called Tetracyclines effective against acne causing bacteria called Propionebacterium acnes .Most of the lesions caused by the microbe on the sebaceous glands will be cleared by Tetralysal as it is a broad spectrum antibiotic. The side effects include overgrowth of other organisms that are not susceptible to the antibiotic, for example fungi or yeasts such as Candida. This may sometimes cause infections such as thrush.In addition there will be inflammation in the colon due to overgrowth of microbes not susceptible to tetralysal and this causes excess of bowel movements and sometimes mucous and blood. Kindly reduce the dosage and stop the tetralysal or in addition consume Lactobacilli Suppliments/such as Probiotics (sold in India as Sporolac Caps Etc).In addition consume more of oral fluids such as fruit juice/yoghurt/tender coconut water etc., The anti biotic induced diarhoea is very much self limiting and subsides on stopping antibiotic and with probiotic therapy. Wishing you a speedy recovery., Best Regards., Dr Lt Cdr ASN Bhushan., Ex-Navy