Brief Answer: this is not a known side effect Detailed Answer: HI, thanks for using healthcare magic Mercilon is a combination of ethinyestradiol and desogestrel which are two hormones. It is most commonly used as a contraceptive. Any bleeding related to an ovarian cysts would be vaginal if it occurred. This is because the genital and gastrointestinal system are separate. It is also not a reported side effect of this medication. Any blood in the stool would be related to some part of the gastrointestinal tract from the mouth to the anus. If the blood was bright red then it is more likely related to the lower aspects of the tract such as the colon to the anus. Bright red blood on wiping only is seen in hemorrhoids, if there is significant pain associated with it in the anal region , it is possibly a fissure. In persons with constipation, blood can be seen on straining. If there is a previous history of constipation or other bowel changes, abdominal pain it may be related to the colon. It would be best to visit your doctor for an assessment. This would include history of any relevant symptoms, physical examination including a pr examination and likely a sample of stool to the lab. If the examination is suggestive, imaging may be needed. I hope this helps, feel free to ask any additional questions

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