Your digestive system is shit
Huh? Wasn't expecting that? Well think about it, you eat food to absorb the nutrients to fuel your body... well what if it's not absorbing the nutrients properly? It would be like topping up your car's tank with fuel, only there's a gaping hole in the bottom of the tank; you're not going to get very far! Your digestive system could be the same; you could be eating substantial calories on your 'I'm bulking bro' diet, but your gastrointestinal (GI) tract isn't actually absorbing the nutrients out of that food. Instead it's either passing right through you and into the toilet, or sitting in your colon fermenting like compost (which is why you probably smell like compost).
This is generally the result of a poor diet and habits. Even if you've recently started eating healthy, it doesn't mean you're suddenly healthy. You need to sort that shit out (excuse the pun). The first few things you can do to help heal, flush out and repair your GI tract are:
A) Start eating more raw, fibrous vegetables and fruit
Fiber helps to push food waste through your GI tract and breed healthy bacteria to over power the bad bacteria in your gut. This will not only help with nutrient absorption, but also significantly help boost your immune system.
B) Take a green superfood powder and high strength probiotic
This is again all part of building good bacteria in your gut. But never take a probiotic alone; if your gut doesn't have a healthy environment for the bacteria to thrive, it won't flourish. This is due to an acidic environment caused by not consuming enough alkalising (acid reducing) foods such as green vegetables, fruits and some grains. You have to therefore first create an optimal environment for the probiotics to even work their magic in.
C) Take L-Glutamine
If you don't already take this to help with the DOMS (delayed onset muscle soreness) from your workouts, then you're missing out big time! What it also is extremely good for is healing the tiny cells in your GI tract that absorb the nutrients out of your food! It also helps boost the immune system and improve tissue recovery (muscle tears from training is tissue damage), so much so that they use it on burn victims in hospitals with outstanding recovery improvements.
Keep in mind, when you train hard you actually tear and damage muscle; that's the stimulus, but it's only when you go home, rest, eat and recover that you grow muscle! The food you eat, or better yet the food you absorb, and the time you allow your muscles to fulfill the healing process, is what actually determines whether you build muscle or not! What you do out of the gym is just as, if not almost more, important than what you do in the gym!