Foul Smelling Stools on Soylent 1.4 and Causes


My boyfriend and I have been on Soylent 1.4 for about two weeks now, but since then, our stools have an absolutely god awful smell. It’s enough to make me nauseous. I’m talking far more smelly than is normal for stool. Has anyone else experienced this? When I looked up foul-smelling stool, I came up with this:

I’ve been on this diet almost exclusively, having a small cup of Soylent for breakfast, lunch, and dinner, and eating some normal food in the evening. At first, everything seemed good. I have IBS-C (constipation type) and I would only have a bowel movement about once a week. Since being on Soylent, things have been more “normal” and I go once daily in the morning now, no issue. Pre-Soylent I had issues with nausea, and I’m still having some now. Lately, I just attributed it to the unhealthy foods I was eating while on Soylent (cereal, funnel cake, lucky charms, burrito, ramen) given that Soylent really improved things bowel movement wise. Now, however, I’m not so sure all of this is a good sign. The smells don’t seem to be getting any better and I have had some diarrhea, far more than normal.

I don’t have celiac disease (tested), but I may have issues with carbohydrates/carbohydrate intolerance (will be tested in the near future) since I know IBS tends to be related to an inability to process carbohydrates. However, the fact that vitamin overdose is also a likely cause is really scaring me. Obviously, I’m going to reduce my intake and make an appointment with the GI ASAP. I still want to know what everyone else thinks and if anyone else is having a similar experience.

Soylent, IBS, the low-FODMAP diet, and gut bacteria

Strange. 1.3 produced much more smelly stools for me. 1.4 basically eliminated it. So, it must be some kind of intolerance for you.


How long were you on 1.3 before transitioning to 1.4? Did the smells ever fade on 1.3?


Do you add anything to your soylent? A lot of people seem to add extra fiber like psyllium husk. I know I add flavorless metamucil which is mostly psyllium husk and I drink 99.9% Soylent with that teaspoon of metamucil. Before I added it my bowel movements were infrequent and burned from what turned out to be excess stomach acid. Since adding it I’m actually more regular than before I switched to Soylent and I can confidently say the odor has not changed to a deadly presence.


If your stool smells like eggs its the protein in Soylent. Nothing to be worried about.


I’ve been recommended a lot of fiber supplements and laxatives by my doctors, but since Soylent, I haven’t really found the need for any of it since things are so regular and I’m no longer constipated. I’m hoping the diarrhea is just because of the crappy food I’ve been eating (pre-Soylent, I rarely had diarrhea, even with crappy foods). It’s hard to tell if all this is a normal part of the transition period or what.