My symtoms. Weight is under average!

I have the following symtoms like from year.. Or more.. But I always thought it's normal and it will be fine on it's own. I was gone to a doctor nearby me, but I was feeling shy to tell about it. 1. Can't release gas (💨) while laying, have to change position or sit, to remove much gas which is not coming out as laying, and then when I sit and try, then it all comes.. In multiple 💨... 2. Sometimes constipation, sometimes diarrhea 3. Itching in anal region 4. Can't empty stomach, Stomach feels full.. 5. Something red appearing out of anal When I try to 💩 6. blood in stool 7. NARROWING of stool 8. Need to drink water again and again,  even have to wake up in early morning, before 3 30 AM for drinking water as feeling thirsty and then urination.. 9. body weight is under average