Many experience problems drinking protein shakes. I hated them. But in the beginning I drank them, three 16-ounce protein shakes a day, in order to meet my protein requirements. You do not have to like protein shakes only tolerate them. There are many varieties of protein shakes available today. Experiment until you can find one you can tolerate.
There are many different types of formulations on protein shakes. I would recommend that you keep experimenting until you find one that you can tolerate. You don't have to like it, just tolerate it. I used Muscle Milk Light (Vanilla Creme) powder blended with water and a half a banana. That worked for me. But on the opposite end of the spectrum, you might try premixed Isopure.
If you tried all the various varieties and still are unsuccessfully, then there is the fallback of fortified milk. 32 ounces of 1% milk fortified by adding 1 cup of dried milk provides 56 grams of protein. It also takes a dent out of meeting the fluid requirements. Mix up a pitcher and drink a little throughout the day.
Without sufficient protein, your body will scavenge protein from other areas of your body, such as your muscles. Protein is extremely important after surgery as its job in the body is to build and maintain tissues including your body's major organs and skeletal muscles. Protein deficiency, when continued over a long period of time can cause a disease known as protein caloric malnutrition. Common symptoms are poor healing, fatigue, hair loss and muscle wasting. Immediate post op, protein promotes healing of the staple line and incisions.
Since you are 3 months post-op, there is another option that has opened up for you. You can begin using protein bars in place of protein shakes. I used Quest protein bars. These bars were good in that they had high protein, minimal sugar and also contained fiber. They also came in a lot of different flavors.
Protein bars are good when you are on the go and can't drag along a blender in order to mix a protein shake.
A Quest protein bar contains 220 calories and provides 21 grams of protein. A Muscle Milk Light protein [2 scoops of powder in a 16 ounce glass] contains 210 calories and provides 25 grams of protein. So they are comparable.