Could be caused by all sorts of stuff when you make sudden changes to diet/lifestyle, but what about these?
– Too much veg too soon. Digesting veg requires a completely different profile of gut flora to your carbs, wine, junk food diet, and the adjustment takes time. Depending on the diversity in there, you may not be able to tolerate certain kinds of fibre well until you find a way to add new bacterial species.
– Salt intake. Cutting out processed foods means your salt intake is dependent on what you voluntarily add to foods. Low-carb diets also increase the need for sodium. Deficiency means trouble maintaining hydration, which is bad news for clogged bowels. Increased thirst, excess peeing, and inability to taste salt are tell-tale signs. Simply drinking more water can further exasperate electrolyte imbalance.
– High doses of probiotics increase gas and would add to any bloating problems caused by the veg. This is probably another case of a need for adaptation. Try reducing the dose until you get things under control.
– Poor thyroid function. High-carb diets can act as a crutch for weakness, and a reduction can bring out the underlying condition. Low-carb and low-calorie diets also naturally lower active thyroid hormone levels. Symptoms include lack of gastric acid and constipation. Be sure you are eating enough calories to maintain good metabolism, and try to eat enough carbs (~60g/day) to keep out of ketosis. If you feel you have other symptoms, get them checked by a doctor.
– Anti-fungals. I’m sure die-off toxins affect bowel function too, but I’m not sure of the mechanism. You’d likely notice other symptoms, like skin outbreaks, if you were constipated with excess toxins, because they’d be reabsorbed.
I’d try reading up about excess PUFAs too. This diet is a great opportunity to reduce an accumulation in the cells (something that takes many months/years), and eating almonds, poultry (much higher PUFA content than ruminants) and excess olive oil means you miss out on this opportunity. Your saturated fat to PUFA ratio seems pretty decent though. I’d try eating yoghurt with some fat, even if it’s reduced, because those lovely fat-soluble vitamins will end up in the toilet (literally) without it. Studies have shown that omnivores can still maintain a low stool pH, so I wouldn’t worry about that level of animal protein consumption as long as it’s nutrient dense and the rest of your diet is pro-SCFA-generating. You could consider mixing in organ meats and bone broth/gelatin to improve the poor amino acid balance of muscle meats/eggs only.