67 King
it seems to me that you are looking to get back in the water very quickly. there is nothing wrong with that but considering everythign you mentioned above, you might want to take it easy. especially if you had a GI, which can weaken you and your immune system. the more intervals you do, the more stress you are going to create for you body and the longer you are going to take to heal and even longer to get in shape. shape is also a big word to live up to, as longer as you are moving, agile, and healthy, youre in shape. try to take it easy, and swim at 65% for 40 minutes, it might do you good. as for your GI, try to find healthy bacteria to replenish your gut flora.
my name is Joey, i swam for team usa and now i work with master athletes in regards to physical fitness and nutrition, if you are interested in learning more, send me a message. Hope all is well.