Did you ever find out what it was that your baby was doind? Did your baby ever stop doing this? How long did it last?
Your descrption is the closest one I have found to what my daughter has been doing lately. No one can seem to give us an explanation.
Her bowel movements are normal, she eats fine, isn't fussy, but will sit for long periods of time pulling her knees up into her chest (just with her stomach musles and back; no hands). She doesn't cry or seem in pain, but is definitely straining, and starts sweating like crazy.
Please let me know anything that you have discovered on the matter. I am pretty worried.
Thank you.