Has anyone had a colonoscopy?

Im only 21 but have to have a colonoscopy next week. I've been having stomach issues for like 7 months. hardness in my stomach, discomfort, abdominal pain, etc. also I've gotten even skinner over the past year, and I'm already too skinny. they think antibiotics have caused my colon to be blocked. ill have to take a laxative before the colonoscopy to clear out the colon. has anyone had a colonoscopy? do you think ill be able to gain some weight after this? maybe its the reason I am too skinny. thanks
Has anyone had a colonoscopy?
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