So before anything, I've been to a doctor about this but just wanted to see if any other parents have experienced this. It's very long, so apologies in advance, but I feel like the more info I give the better.
So this is my first baby, and she's always had seemingly a lot more issues with gas/pooping than is considered normal (when I say 'issues' I mean real fussiness and sometimes seeming to be in agony purple-faced screaming crying arching her back in clear pain and distress) but all poops normal, gaining weight normally, HV unconcerned etc so we just were left to cope with it really.
However at around 10 weeks old she suddenly increased how much she was feeding. It changed from every 3-4 hrs feeding for sometimes well over an hour, to suddenly feeding (at most) every 2.5hrs for 5-20 mins and sometimes feeding 5-20 mins every 20 minutes! At first I thought it was a growth spurt but it lasted over 3 weeks like this. Along with the sudden increase in feeding came an increase in pooping (around 4-6 poonamis a day!) This became the normal amount she'd poop, and gradually she seemed to be regularly wanting feeds roughly every 2 hours and would feed 10-30 mins on one breast, switching to the other for the next feed (unless she'd not fed for long in which case I'd offer the same one, or if she drained one and was still hungry).
As the weeks went on she seemed like she finally was coping a lot better with gas and pooping, and was in something of a regular pattern and sleeping through the night too.
Fast forward to when the problem at hand all started: at around 15 weeks (she's now 17 weeks).
She suddenly is only doing 1 poonami a day (if we're lucky) and she's had maybe 2 that have been a normal colour in these past 2 weeks. The rest have all been green and usually with mucus/stringy looking stuff. And until she actually does the poo it's like we're back to square one as it's making her writhe around purple-faced screaming and crying in agony again. It almost seems like she's straining sometimes but all of the poops are liquid, the last one 2 days ago was quite watery too. When she actually DOES the poo she's completely fine, pushes it out and doesn't cry at all, so it's like the issue is happening when it's in her intestines or something??? I will add that she's having plenty of normal wees, so no issues there.
I can't see how it could be a fore/hind milk imbalance because I'm very careful to make sure she's drinking long enough to get both and when I sometimes have to check if she's crying because I've ran out of milk, I squeeze and the milk is white (which I assume is the hind milk).
We've done all the usual tips like the bicycles, baths, tummy massages etc but not helping.
She is otherwise fine. No fever, no illness, gaining weight, feeding normally (unless she's in a lot of pain, in that case it can interfere sometimes). For the past 4 days I have cut out dairy and eggs in the hopes that it might be either of those (I was allergic to cows milk as a baby but grew out of it) but so far no change at all in colour, frequency or her obvious pain and difficulty.
Took her to the doctor today and she hadn't a clue so she wants a stool sample and have to wait for a call from paediatrics, and to just carry on without dairy. She has her 16 week vaccs on 1st March and I'm dreading dealing with the after effects of that on top of all this - she had an unusual reaction to the 8 week 6-in-1 2nd dose where her entire thigh went bright pinky-red 5 hours after the injection and was very fussy, called 111 but it eventually faded away an hr after I called so the on-call Dr was happy not to see her, but this made me concerned about possible allergens as I know some vaccines contain egg proteins for binding or something so now I'm worried about her 3rd dose, and whether it could be eggs she's allergic to/intolerant of.
But again, this is all a sudden change and I never changed my diet in all these weeks! Again I'm sorry this is so long I'm just really struggling to cope at the moment and wondered if anyone else had experienced anything like this? TIA for anyone who's taken the time to read this whole thing.