I can respond quickly because I'm on the computer at this time. If there's no responses back to threads once I'm done...I leave, lol. You've responded, so I will as well.
You need to realise that you're new to the game and learning while in a stressed time of your life. It'll take a while.
The oral meds won't fully keep the UC from spreading past the rectum since the sigmoid won't be fully covered. That's where the enemas come in.
Unless you had a patch in the cecum and some changes in the biopsies throughout....the dosage you're on can help keep the rest of the colon quiet while you're healing. It's not going to skip the rectum inflammation and spread downward or separately.
But....your symptoms will give you insight if there's any changes, especially regarding the type of stool you'll have. If it becomes looser....then the area will probably have encompassed the entire rectum and if diarrhea, it's up into your sigmoid.
But, keep in mind that food can have an effect on the functioning of the gut....and some will cause you loose stool and diarrhea. But, once it's out, it wouldn't continue...if things continue, then it warrants a second look on what's going on via recto/sig scope and/or stool samples to make sure it's not an invader (since they pass from hand to mouth).
Deal with what you have at this point. Since it's very low in the rectum...it can sometimes respond slower.
Your food intake...try to keep it as balanced as you can, and wash your hands before you eat and often throughout the day. Don't forget to clean your cellphone periodically. I clean mine once I get home with lense wipes by Zeiss. I'm not saying get obsessive, however....just be aware.
You could start a probiotic to take at bedtime. It won't affect the mesalamine.
Other than that...create a plan to discuss with your doctor and go from there. Extremes aren't warranted at this point. If the mesalamine isn't enough then there are steroid supps that could be added or alternated with the mesalamine to give an extra boost.
Hang tough....
q