this is most likely very much the normal healing curve. After my surgery even with miralax and stool softeners with all the swelling the stool did not want to come out...it tended to get to the half way point and then stop....what ever you do don't bear down hard to get it out....I would just take baby wipes and clean myself up until the next time and eventually as the swelling went down the having a bm became easier.
The pinching is most likely muscles spasming as they are trying to figure out how to work. Remember you had a lot of work done inside and things will not be normal for quite some time...try to be patient and know things will get better.
Are you still on narcotic pain killers? Those slow your peristalsis but it is a double edged sword as we need to stay ahead of our pain, but don't want to be constipated. I use magnesium supplements for the spasms...but if in doubt always best to contact your surgeon if for no other reason then to have them take a peek to reassure you all is healing well.
2 1/2 weeks is still very early in your healing curve. Are you BMs soft? Straining to have a BM is not recommended, and although you have swelling from your operation you may wish to speak to your surgeon to see if you can use a higher dose of Laxido or consider another option. You could also rest your mind at ease by getting a check up see how you are healing. Be careful not to over do it. What restriction have you been given with regards to lifting and general activity? Full healing can take 12 weeks and it is worth adhering to the healing guide lines to get the best result possible
I hope this helps.