I had seen your medical presentation and understood the true concerns of your condition. First of all brown streaks are formed as a result of torn connective tissues located in the dermis (skin layer). There are any causes for brown streaks, but the most common are weight gain, hormonal changes, repeated use of topical ointments etc. There are very minimal chances of getting brown streaks in rectal prolapse. The you have to go for the following investigations to know the exact cause: 1. check your weight (to see any sudden weight gain) 2. colonoscopy (to check rectal prolapse) 3. estimation of cortisol hormone (any increase in hormone level) Coming to treatment part, you can follow the below: 1. avoid spicy dieting 2. eat a balanced diet rich in vitamins and minerals 3. consuming a suitable amount of vitamin A and C 4. aim for slow and gradual weight gain 5. apply some moisturizer cream Hope you could understand all the relevant aspects and act accordingly. There is no need to worry but act soon to avoid further complications.